Sorry, but that's just not true. If you were to head east, you'd find plenty of them very quickly. You're just used to thinking of the Lighthouse as being a dead end.
Paisly is the capital. It's a rather long way to the lighthouse from Paisly. These intra-realm sea routes aren't particularly short, you know? And on the rare occasions I do see scout reports from Sallowtown, Sallowwild, and the Desert, rogue forces are rather small if there are any at all.
Further, a few small battles with the rogues isn't enough to stave it off significantly. One needs huge battles. However, one can't muster huge battles if TMP halves your units' training by the time you reach a fight.
On BT, I haven't seen much rogues either, and even if we went out of our way to fight some in rogue regions, it still wasn't enough, in combination with actual battles against humans, to stave off TMP. Not every realm has access to a large body of rogues to entertain them like Astrum does. Being very large indeed allows them to border many wild lands, and gives them a sizable mobile force. Many smaller realms have a much smaller % of their fewer nobles that are actually part of the mobile army, and aren't traders, courtiers, priests, and/or ambassadors.
