I agree outposts need to be overhauled.
My full suggestion:
I prefer my levelling idea for outposts- that's simpler- can be shown graphically more easily, and is less micro-intensive (so will help AI)
I'd suggest a 5-level system
Lvl 1- outpost that does nothing other than ZOC
Lvl 2- outpost gets a warden effect that works on "Weak" monster or player stacks, +10% att/def,
Lvl 3- outpost gets a warden effect that works on "Medium" monster or player stacks. +20% att/def, special bonus based on town pioners come from
Lvl 4-outpost gets a warden effect that works on "Strong" monster or player stacks +30% att/def, +1 ZOC (high tower)
Lvl 5- +50% att/def, -10% unrest , upgrade to special bonus
outpost bonuses do not stack
Special bonus at lvl 3/5
Towns or lvl 1 settlements: +.5/+1 growth
Forts: stables/caltrops
Conclaves: -25%/-50% cost to tactical spells. Arcane monoliths also provide this.
Upgrading a settlement takes production. Casting arcane monolith will also increase an outpost by a level.