So I bumped up the difficulty....Now I understand

[katank]

This doesn't seem to happen in Shogun 2. In my last Legendary Chosokabe game I took both Iyo and Sanuki while the Kono and Sogo Daimyos where still in the field. Neither of them disappeared, rather they were labeled "Kono/Sogo Rebels" from then on. A nice addition!

I haven't figured it out yet but sometimes the stack disappears (major/minor factions?). At any rate, the rebels are far less dangerous (they won't venture outside of the province they're in).

[Papewaio]

So non-wandering ronin armies. Seems a tad ironic and not very sporting.

Is there any triggers to spawn legendary ronin from such stacks... Love to seea Red Beard ronin figure going up against the lowest honor clans.