Well, I'm not a huge fan of the idea in all honesty. The math and rules involved add complexity when I don't really see a need to have such a mechanic in the first place. Would 5 imps at first or 100 imps later even make a difference? I doubt it. And as in for manager roles, your constructs and actual creatures do that.

Sorry if I come across as angry or dismissive, but I fail to see why we need to do this with the imps or how it would really matter, and so I can't say that I support adding it in.