Also, if you have lock down for fiefs, everyone who wasnt part of the ten largest clans, would be locked out of being able to do anything. in other words, it becomes a game for the mega-clans and everyone else is ass out, and has no reason to even attempt playing, which means, yeah maybe YOU get what you want, but the Strat community doesnt grow, it probably shrinks, and what your left with is a social club for 200 people.
I mean, how can anyone raise an army to claim a feif or even fight, once all the fiefs are claimed? Its already hard enough as it is to break in against the mega-clans with the file cabinet full of CD keys...
And a social club for 200 people, aint going to prosper, improve, expand, in fact, its likely it will go down in flames when those 200 get bored with it.
What strat needs, is more fiefs, with more cost to control them, for particular guilds, depending on how far they are from a declared 'capital city', AND additionally, something almost opposite of what your asking for: A morale factor in all fiefs, that decreases as the current owner ups the visiting fee. This would result in a higher cost for an over-expanded empire, while retaining viability for a smaller entity to control one or two 'close together' feifs at the current cost and organization.
When a particular town's morale gets to a certain 'lowpoint' it should trigger a 'peasant revolt' which then schedules a battle - the disgruntled townspeople versus the current tyrannical owner and his loyal army...
THIS i think would make things alot more dynamic, changing, challenging and, fun for more people.