To add: I think it should take time over a day or two or longer. Then it is risky for you, because you can get captured in lands with which you are at war, or someone might spot you and wonder what you are up to.
Of course, to balance out this request, there should be a another one that suggests peasants be a lot more uppity in general, otherwise as soon as you see a random peasant mob form, you will
know what they are, and plan appropriately. It will still be a nuisance, but no more than a large monster/undead mob (except the doubt over
exactly how strong it is).
There are some very, very rich characters, this could be devastating.
I can think of one possible abuse scenario: a conquering army enters enemy lands, spreads out, summons mobs, then regroups
Only if they are all diplomats or infiltrators...
