Changing Liberation army to the Option of setting up an outpost after destroying an enemy outpost would make the virtue much better, since it is required for Special services.
This would make skirmishes around outposts and the importance of protecting outposts more important since it would allow for aggressive players to remove enemy outposts wtihout having to worry about expanding at in opportune times.
It would allow a player to prevent/stall/contain an enemy from expanding without having to wait for the outpost to become a city and then raze it.