Here's a system I think could work (probably will be in a DLC but whatever).
Have the Roman pops organized into the assembly of the plebs, assembly of the centuries, etc. that existed historically and vote in these for the two consuls and offices as appropriate. (similar to elections in vic 2 where the player can have some influence). You would also need to allow the player (and the parties??) to bring about intrigues (bring in gladiators to 'convince' the voters to vote a certain way, bribery, forming street mobs etc.) that raises tyranny but increases vote share (this would help simulate the fall of the republic later in the game as each side starts forming their own street mobs and such)
This gives you 2 consuls, each organized behind a party's platform, and can also be used to elect lower officials.
A few advantages of this system are as follows:
1. It can simulate the disfunction that occurs when 2 opposing consuls are elected (Julius Caesar and Bibulus come to mind).
2. It is still possible for the player to have influence (get your friends/allies in the consulate to get the policy you want). Even with 1 year consuls
3. Faction influence matters more (a faction may be small in the Senate, but if popular enough among pops can still ruin you through tribune vetoes).
4. It forces the player to decide between following the conventions of the republic, or getting what they want but raising tyranny. (e.g. shutting out/threatening the tribunes, intimidate the vetoing consul, etc.).
5. It is better able to simulate trying to hold the republic together, especially near the end.
6. Allows more flavor in passing laws to change the powers of each assembly (similar to changing election laws in vic 2) as well as more accurate Roman politics (dealing with street mobs would be an interesting event)
To address the issue that 1 year elections hurt your ability to act. That was why the Romans choose them, and I think from a gameplay perspective it is interesting as it forces you to choose between getting new people all the time who may disagree with you and stymie your plans, or keeping in your golden consul (Gaius Marius) but raising tyranny a bunch.
Sorry this is a bit of a mess, I am just putting out a bunch of thoughts. I do understand that their are limitations on dev resources and time during development, but I would like for this to be implemented at some point (DLC would be fine).
This right here. Honestly, I could have dealt with the one consul thing. And the pseudo-council that's supposed to represent the Cursus Honorum. But seriously elections for a historically elected position like Tribune of Plebs not being in the game? Or am I misinterpreting this wrong and can it be changed by a change in the Republic's electoral law? I understand that there are many nations in the game, but I don't know. I would expect some unique internal and external mechanics for the nations that shaped this era of history, Rome, Carthage, Alexander's Successor States, the major states, there should be something unique about playing The Roman Republic and not be the same as playing as Mediterranean city-state #84. I understand not having things like a fully historic Cursus Honorum as there should be a balance of gameplay and historical accuracy. But all of this just seems like your throwing historical accuracy out the window to needlessly streamline and simplify the game, I mean, god man, were not HOI4 players.