I don't want an ahistorical Russia....Never said anything about it. And either way, WW1 Romania had nothing to do with Russia.
Started 2 games as canada and just watched WW1 unfold.
First game - Historical WW1 end
Second game - Historical WW1
Right now i'm on the Historical WW1 save and
1. Romania never joined WW1. They just stood there being neutral.
2. Versailles treaty gave Bassarabia to romania and Transylvania to Austria. (which quickly became Hungary).
3. Soviet Hungary did declare war on Romania, but since Hungary had more land, more manpower, etc the peace between the 2 countries was a white peace. Transylvania is still owned by Hungary.
I looked through the mod files and some events required for a historical Romania are there. They just won't trigger.
This is what should happen on a Historical WW1:
1. Romania joins the war in 1916. (it never did join on my play throughs)
2. Shortly after the Soviet union makes peace Germany and Austria-Ungaria make peace with Romania.
https://en.wikipedia.org/wiki/Treaty_of_Bucharest_(1918)
2.1. This peace treaty gives Bassarabia to Romania, and Germany+Austria-Hungary takes the southern part. That was the richest oil region west of the Black sea.
3. Shortly after the war ends Romania gets the Proclamation of Union event. This gives Transylvania. (<- could be grouped up with the versailles event)
4. Because of point 3 Hungary declared war on Romania. (1920) (and it even makes sense, right now in my playthrough Hungary has the land but still declared war)
5. The war ends with a white peace and a new Hungarian government.
Here's a nice gif showing what i mean. https://en.wikipedia.org/wiki/File:RomaniaBorderHistoryAnnimation_1859-2010.gif
So no, even if you pick Historical WW1 or Historical WW1 end Romania isn't historical. I get it, nobody cares about such a insignificant country.
Without a historical romania:
1. Little Entente is pointless as it was an alliance made to prevent Hungary from expanding.
2. Second Vienna award makes no sense.
I'll show myself out, it seems that i'm supposed to make my own mod if i dare to point out some historical inaccuracies.
First of all welcome to Paradox games, where everything becomes always ahistorical, any time, as soon as you unpause the game. Which is great and good that way, or otherwise you always have to play as the alllies to win.
Second, AFAIK Romania joines, once Russia controls certain key provinces in galicia, then they will join. Sry, I don't know much about Romanian history, but that seems pretty plausible. So I guess the Russians failed to conquer the key provinces. Tough luck, but happens.
Third, in all of my countless playthroughs, i never ever saw Romania lose the war against Hungary. Never. Again, it seems you either had tough luck, or a treaty event still has to trigger, which gives them both the historical borders. I had always the right borders in the end.
Oh, and another thing, did you look at the sheer size of the mod? Do you really really think everything i done already, both historically and ahistorically? Listen, nobody in this mod ever said anything about Romania being insignificant. Because, spoiler alert, it isn't. But, and careful here comes another spoiler, we kinda have to concentrate on the big nations first, because more people play them. So instead of rage quiting a mod because something happened you don't like in one or two playthroughs, and feeling personally attacked (by whom? I'm literally the first one in this whole forum who is a bit unfriendly to you...) why don't you calm down, start a new game and look, if it's different. Or play as Romania, and just try a world conquest with them, may be hard but fun, i guess.