Actually, if you think about it, Vimes already *HAS* created his own Justice League.

That's what The Watch are. They have abilities normal folk don't, and they fight crime. Mostly in their home turf, sometimes outside it.

And then they become an instrument of institutional change, and incorporate an ever growing army of outside-the-box types. Kinda like JLU. They do it all with the tacit approval of the government.

I have had this very idea before, actually. The "Batman on Discworld" thing. I'll post something....