Interesting discussion - but I think it's showing that there is no obvious and fair-sounding way to engineer the decline of large empires. Tet has a lot on his plate already. Maybe this is just asking too much.
As far as I'm concerned, the most important reason for wanting to break down huge empires is not to prevent AI conquest but rather unhindered human domination. For this reason, "degraded" AI units will only make the problem worse.
As a matter of historical fact, continent-scale empires break down through a process of secession: a chunk of the empire declares its independence from the empire's capital. There is absolutely no mechanism in Civ3 to simulate that - the closest analogue would be to institute a brief (5-turn) era where outlying cities have a 10X probability of culture-flipping. Again, I don't know the limitations of the editor and I suspect this is unbuildable, but it might be interesting.
A different sort of solution would be to have an era where all units cost 5 gold each to upkeep. That would quickly bankrupt states who run huge armies of occupation, and their troops would start dying out. Of course, a state like that would just send their expensive soldiers to their deaths in a massive war, and that might not really improve anything. Yeah, this is a hard problem that we probably shouldn't expect Tet to solve.
I would prefer that the focus be on the prevention of easily-acquired, gigantic empires, such as a united Europe. Improvements in this will hopefully make empire-breaking a less urgent matter.
As far as I'm concerned, the most important reason for wanting to break down huge empires is not to prevent AI conquest but rather unhindered human domination. For this reason, "degraded" AI units will only make the problem worse.
As a matter of historical fact, continent-scale empires break down through a process of secession: a chunk of the empire declares its independence from the empire's capital. There is absolutely no mechanism in Civ3 to simulate that - the closest analogue would be to institute a brief (5-turn) era where outlying cities have a 10X probability of culture-flipping. Again, I don't know the limitations of the editor and I suspect this is unbuildable, but it might be interesting.
A different sort of solution would be to have an era where all units cost 5 gold each to upkeep. That would quickly bankrupt states who run huge armies of occupation, and their troops would start dying out. Of course, a state like that would just send their expensive soldiers to their deaths in a massive war, and that might not really improve anything. Yeah, this is a hard problem that we probably shouldn't expect Tet to solve.
I would prefer that the focus be on the prevention of easily-acquired, gigantic empires, such as a united Europe. Improvements in this will hopefully make empire-breaking a less urgent matter.