I think pretty much everyone will agree, when thinking of their own realm out of context, that they would much rather their success and growth be limited by their own capabilities, than hard-coded limits to what they are allowed to strive for.
The inherent troubles of fighting far from the capital and defending a large territory are the fairest and most fun restrictions to growth. You end up with lots of equipment damage, rations can be an issue, salaries, troop losses from battles, the inability to be everywhere at once, etc. Because these allow players to do their best, and these allow skilled players to shine. IC action and coordination are rewarded.
Hard caps that can only be overcome by OOC actions, like recruiting more players (or multi cheating, because let's not pretend that cheating will never again occur and that these mechanics don't give huge incentives for it), are the least fun. They prevent players from even trying, and tend to just make realms sit contently on their asses, unable to aspire for more, just waiting to wither away.
Large realms were one form of behemoth. But we still see behemoths anyways. Obeah on BT, if you removed the rogues, could still just steamroll everyone, and moreso than ever, because the difference in noble count means the other realms, for the most part, just struggle to maintain a livable core of regions that will both produce a minimum of wealth and feed their capital. If you look at Luria, everyone tells me that it's "dead" since the secession. In Westgard, my greatest fear is that we become "too successful". If we reach a hard cap, I strongly fear that it may demotivate players, and plunge it into a spiral of decay. Less players, a lower cap, which in turn drives more players away, and so on. We've had cycles of various sizes, but at least it was always the result of glorious combat, not hitting an super meta gamey limit on density. But to return to behemoths... the large realms were, in my opinion, needed to balance out the dense realms. Luria and Rio are examples of dense realms, a small cluster of rich and fertile regions that tend to attract lots of nobles and benefit from low distance from the capital. Luria fended off the whole continent united against them, even when they had lost many regions. Rio held its own quite well against Enweil, when it didn't have other realms helping against it. I mean, in a sense, Luria was "stifling", D'Hara could not, ever, stop thinking about the Lurian menace. But... there was also the North. We couldn't even stop thinking about the northern menace. And the Zuma... and the various realms that tried to colonize our islands when we lost regions to rogues. But it was thrilling nonetheless. Same thrill as when I commanded the armies of Enweil against invaders from all sides, in 2009. It wasn't about being an overpowered realm, quite the contrary, it was about the stakes being sky high, and player agency being determining for what would happen next.
