kristoff said:
Take goverments - why do they just give a simple bounus to this or that. Considering how it was important (afterall bulk of Roman history is struggle between kingdom v. republic and then republic v. dictatorship) government types should mean much more - having impact on taxes, recruitment speed, trade incomes, ability to assimilate foreigners, army or navy values and so on.
Right - more diversity, and complexity is always welcome.
The problem lays with duplicating effects, You already have ideas (more so than in EU), as well as omen: so there only are so many variables You can elaborate on, before You create some overlap.
Aristocratic Monarchy does give a trade bonus (25%), I believe - which translates to a hefty pecuniary advantage, especially later ingame.
Military Republics or Tribes give discipline bonuses to their units.
Taxes, recruitment speed and assimilation time are not considered by government forms - on the other hand.
You also need consider character's impact on the game, thus You
already have "Governors" affecting assimilation chances, as well as tax income.
Your reflection, considering the Roman struggle between Republic, Empire, Dictatorship and in earlier times Monarchy, is very relevant.
There is a fundamental difference between Republics and Monarchies, as it is. The former see their rulers "elected", meaning popularity, charisma and oftentimes family prestige, will matter: which enables one to prefer some potential rulers, over others (one can also assassinate characters).
Ruler's values (Military, Charisma, Finesse) influence the nation, and thus Republics are quite distinct, in that, from Monarchies, Dictatorships, Theocracies or Tribes - regardless of bonus
es.