I disagree about global game balancing because it seems to me that the changes in HTTT broke much of the game balancing of the years before that anyway. Just look at what Castille regularly does in North Africa. I think that the new system will give a more realistic end result, because I thought the "the capital is magically unannexable" rule was a bit silly and immersion-breaking.I never really saw this to be strictly a game balancing issue (though it certainly was that too); I always thought this was meant to model the pattern of a succession of wars which went in one direction, ending in eventual annexation. This seemed appropriate because it simulated the decline and defeat of the rival country, rather than its abrupt non-existence.
(I completely agree that it shouldn't be usual to annex countries the size of northern Italy in single conflicts, but then it shouldn't be usual to force-vassalize them in single conflicts either. I also agree with your point about multiple wars being required to destroy most powers, but if you're able to strip all the provinces but one from the country on the first war, as you often were in HTTT but not IN before April 15, a second war against the OPM that's left isn't very impressive.)
Some detail on some ways HTTT broke the old balance:
- "Legitimacy." 4 less revolt risk in every province for the player, and for AI's which happens to have lucked in to 100% legitimacy, stacking on top of stability... and then we wonder why Castille overruns North Africa every game. 4 more revolt risk in every province for an AI that loses legitimacy (a player can manage legitimacy but the AI doesn't know how), again stacking on top of instability... and then we wonder why AI's "balloon" now.
IMO, to keep balance, 100% legitimacy and +3 stab should have had the same effect in HTTT as +3 stab had in IN. If Paradox wants to change that, fair enough, but do plan that you'll have to rebalance because of it.
- The CB system. It's nice in many ways. But it seems to me that the bonus to your "peace cost factor" on the "good" CB's makes the typical war more decisive than it was in In Nomine. This would speed blobbing up even without being able to annex in one fell swoop.
- "Military tactics". The effectiveness of your troops is now roughly proportionate to the third power of your land tech (better unit types x better offensive casualty multipliers x better defensive casualty dividers), where previously it was only the second power. Since the player will be leading in land tech...
- And then there's the obvious: we can now reliably get 5-star advisors of whichever type we want, whenever we want them, as many as we want. It's nice that we don't have to wait for a random event to throw up a 1-star irrelevant advisor every ten years, but, perhaps, this is a bit much? Balancing of the advisor types? Diminishing returns for multiple advisors of the same type? Borrow some of the mechanisms for land/naval tradition?