I had a fun moment as Dale just now. I'm in turn 51, and conquered most of northern Rhùn but my spies showing three full stacks coming in from the south and one returning from the west after Edoras was captured by Isengard. I've been taking some chances, using spies to gain instant access to towns without the need to lay siege, and stretched myself pretty thin.
Seeing this situation I decided to pull back, sack two of the towns and come back later on when I'm at full strength. Crossing a bridge I notice Loke-Khan trying to hide in the bush with three troops and I'm having 3/4 stack at 80% strength so I decide to try and wipe him out on my way back to let me feel better about having to retreat. This was easy enough, and when I return to the strat-map that's the end of Rhùn
I'd managed to assassinate two generals earlier, I guess it was the last of his bloodline, so when he went so did his kingdom. Well, just mopping up rebel settlements now before going after Harad or even the backdoor in to Mordor.
That's dope man it reminds me of this time in broken crescent where I got half of southern India to revolt by using priests as the ere lol I would take half their providences without going to war with them lol I also uses assassin and spies to increase disorder
I've had this happen a couple of times in other games, but usually not before I'm closing in and they got a settlement or two left. Funny how things can turn out some times

Spies, assassins and diplomats are powerful tools.