Legs,
A lot of +0 Ninja gear at Ayn Assuadi. Some of it has been loomed, most of it not. 0 is better than none.
Also, for those looking to get back into Strat... adding onto Bryggan's post...
Declare your wars. Rather than seeing the 13k, or any of the active factions, leave because a battle got ninja'd... make sure you declare your wars. I'd say give the faction 24 hour notice. Don't get all your armies in position right outside a fief, declare war, and then hit the attack button. By giving a grace window, you allow 'tension' and 'hostility' to grow between the two factions. There's also a chance the faction, afk or not, might be able to get a call out for aid. Everyone would have 'scouts' out there anyway. A farmer, planting his field sees an army of 200 marching east... toward's his home, or some such.
And in the event of an undeclared war, why not have all active factions sign up for the defense? Again, even if it's for an afk fief owner... 1) The merc pool is reduced for the offender. 2) The defender may be able to muster a defense merc wise, and become reengaged in strat 3) You truly penalize the offender by costing them an army.
Oh, and let's also say this... The defending party can, and should do a ninja upon the attacker. Why? The attacking party wasn't really looking for a fair fight now were they? ;-) You want to play by the rules of engagement, play by them, and flourish for all. Just a thought.