[Shovah32]

Corwin, in most maps (unless your stuffed in a corner or against the sea) you have plenty of provinces connected to your castle (even if you dont you could always expand a little more, just keeping it compact) and, by capturing all the provinces round his castle he will have alot of resources coming to where they are needed to produce useful troops. Unless the enemy takes a very long amount of time to reach you there shouldnt be a problem with expanding too far away from your castle and, if you do expand far out you can 'bust the dam' on some indies, finding the enemy with the nice units you produced at your castle.

Another nice little trick (that can fail very easily) is trapping enemy armies, when the enemy attacks you (and gets into your empire) use stealthy, flying and summoned armies to cut off their retreat, use some sort of assasination/spell (dreams of rlyeh, seeking arrow, recruited assasins, summon tupilak, stealth units with black hearts ect) to take out all the commanders (you need to REALLY do this en mass to make sure ever commander is dead) then you can march in with a single unit and rout the entire enemy army (hopefully a very large, expensive one) and have then destroyed because they are cut off.