this is long, so there's a tl;dr at the bottom
How the precursor event chains usually work in the current version is as follows: You very quickly discover the remnants of a precursor empire, often times in your home system. From there you'll discover the usual mixture of anomalies and among them will be some precursor signs, usually giving you 2 or 4 artifacts in total. Then after an arbitrary amount of time an arbitrary artifact arbitrarily appears amongst your... umm... your planets (randomly went into alliteration there
).
While this is all fine and dandy and the random spawning of anomalies helps ensure the chain can end, there's still a problem here: the fact that this all depends entirely on random chance means that, by murphy's law, you're STILL not likely to complete a chain by the point you're expected to (which, based on the reward, is between early and mid-game). It's even worse if you complete a chain and the anomaly doesn't even spawn for whatever reason, even though you're ABSOLUTELY sure you discovered the planet first, and it's worse still when you get the random artifact appearances and they don't actually appear! (yes that happened to me, twice in the same game).
This leads me to the following question: Does the precursor event chain, or many chains in this game for that matter, need to depend on RNG? Or, at least, does it have to entirely depend on it? The way this game is made using RNG to create other empires gives it an immense level of replayability, but certain things are absolutes as far as we are concerned: we will always get a precursor chain to follow. And if we know this, do the clues have to be or even ought to be found by completely random chance?
I feel like most people would say yes, and use the following argument: Randomness in core gameplay leads to more variety. If we had the exact same scenario for each empire each time we played the game, the game would get pretty dull very, very fast. As I said before, the RNG behind empire creation gives the game immense replayability and reducing the aspects of RNG would not necessarily be a positive thing.
However, you have to bare in mind that when you leave something to random chance, you completely lose control over it. All you can guarantee at that point is "this MAY happen." we MAY find a bunch of artifacts right from the get go and receive the others later. You can't guarantee HOW it will happen either; maybe you'll find all six artifacts within the first decade of gameplay, or maybe it will take until you rule the entire galaxy to complete the chain.
While RNG is good for the precursor chains to a degree, it has a lot of clear weaknesses. This is why I think there should be a level of pre-determined mechanics behind the precursor chains, and potentially some other story-related things. There are two reasons why I believe this.I suppose if you're still reading then you'd like to hear them 
First, and most obviously, it would ensure an empire would be able to complete the chain. If the pieces don't require discovering anomalies by random chance then we'll eventually stumble across them through normal gameplay as we currently (usually, but not always) do in the current version of the game. This would be significantly less frustrating than what we have now and could lead to more sensible chances for story content.
On that last note, my second reason is thus: More chances for interesting story content. One of the things I love about the end of the precursor chain is the interesting lore behind the race that you can witness just from looking at the state of their fallen world, a constant reminder of what once was. But you only get that at the end of the chain and we rarely get to see that. In the Cybrex chain, for example, we're aware that one alien race killed their entire planet as a way to prevent their robotic conquerors from doing so. But that is never portrayed effectively when it happens on a tropical world that I've firmly established as one of my planets. Imagine finding planets, ruined stations, or even entire systems dedicated to a chunk of lore on these precursor empires. Finding a broken planet with ancient space ruins floating above is a much more telling sign of the immense conflicts of long ago. Heck, you could be even bolder and tie in the fallen empires to the mix, or give us special technology for discovering artifacts first. Plus, if the artifacts had a sense of pre-determination, you could end up with situations where the politics of empires comes into play. The point is that by exercising a level of control over content like this, even if it's only through a handful of planets that are given precursor artifact status, can make the story tremendously more interesting.
So in conclusion, I think certain aspects of Stellaris's story, like the precursor chains, should be a bit less RNG. This is not me arguing for a rigid galaxy; certain things only work if they are completely luck-based, such as the horizon signal (WHAT WAS WILL BE!!! WHAT WILL BE WAS!!!). Even a small amount of more direct control would enable the developers to make something truly intriguing and really flesh out the story of the ancient galaxy.
How the precursor event chains usually work in the current version is as follows: You very quickly discover the remnants of a precursor empire, often times in your home system. From there you'll discover the usual mixture of anomalies and among them will be some precursor signs, usually giving you 2 or 4 artifacts in total. Then after an arbitrary amount of time an arbitrary artifact arbitrarily appears amongst your... umm... your planets (randomly went into alliteration there
While this is all fine and dandy and the random spawning of anomalies helps ensure the chain can end, there's still a problem here: the fact that this all depends entirely on random chance means that, by murphy's law, you're STILL not likely to complete a chain by the point you're expected to (which, based on the reward, is between early and mid-game). It's even worse if you complete a chain and the anomaly doesn't even spawn for whatever reason, even though you're ABSOLUTELY sure you discovered the planet first, and it's worse still when you get the random artifact appearances and they don't actually appear! (yes that happened to me, twice in the same game).
This leads me to the following question: Does the precursor event chain, or many chains in this game for that matter, need to depend on RNG? Or, at least, does it have to entirely depend on it? The way this game is made using RNG to create other empires gives it an immense level of replayability, but certain things are absolutes as far as we are concerned: we will always get a precursor chain to follow. And if we know this, do the clues have to be or even ought to be found by completely random chance?
I feel like most people would say yes, and use the following argument: Randomness in core gameplay leads to more variety. If we had the exact same scenario for each empire each time we played the game, the game would get pretty dull very, very fast. As I said before, the RNG behind empire creation gives the game immense replayability and reducing the aspects of RNG would not necessarily be a positive thing.
However, you have to bare in mind that when you leave something to random chance, you completely lose control over it. All you can guarantee at that point is "this MAY happen." we MAY find a bunch of artifacts right from the get go and receive the others later. You can't guarantee HOW it will happen either; maybe you'll find all six artifacts within the first decade of gameplay, or maybe it will take until you rule the entire galaxy to complete the chain.
While RNG is good for the precursor chains to a degree, it has a lot of clear weaknesses. This is why I think there should be a level of pre-determined mechanics behind the precursor chains, and potentially some other story-related things. There are two reasons why I believe this.
First, and most obviously, it would ensure an empire would be able to complete the chain. If the pieces don't require discovering anomalies by random chance then we'll eventually stumble across them through normal gameplay as we currently (usually, but not always) do in the current version of the game. This would be significantly less frustrating than what we have now and could lead to more sensible chances for story content.
On that last note, my second reason is thus: More chances for interesting story content. One of the things I love about the end of the precursor chain is the interesting lore behind the race that you can witness just from looking at the state of their fallen world, a constant reminder of what once was. But you only get that at the end of the chain and we rarely get to see that. In the Cybrex chain, for example, we're aware that one alien race killed their entire planet as a way to prevent their robotic conquerors from doing so. But that is never portrayed effectively when it happens on a tropical world that I've firmly established as one of my planets. Imagine finding planets, ruined stations, or even entire systems dedicated to a chunk of lore on these precursor empires. Finding a broken planet with ancient space ruins floating above is a much more telling sign of the immense conflicts of long ago. Heck, you could be even bolder and tie in the fallen empires to the mix, or give us special technology for discovering artifacts first. Plus, if the artifacts had a sense of pre-determination, you could end up with situations where the politics of empires comes into play. The point is that by exercising a level of control over content like this, even if it's only through a handful of planets that are given precursor artifact status, can make the story tremendously more interesting.
So in conclusion, I think certain aspects of Stellaris's story, like the precursor chains, should be a bit less RNG. This is not me arguing for a rigid galaxy; certain things only work if they are completely luck-based, such as the horizon signal (WHAT WAS WILL BE!!! WHAT WILL BE WAS!!!). Even a small amount of more direct control would enable the developers to make something truly intriguing and really flesh out the story of the ancient galaxy.
my answer to this question is no because it reduces annoyance related to the chain and opens up opportunity for more in-depth storytelling.