taking advanced resources other players invested in...worth a VP?

There's too much context missing to definitively comment, but on the surface it sounds ok. If I've trained (i.e. created) the worker, he reports to me. I can lend him to you for an action, for which you pay me one VP.

But it depends on how valuable VP's are, and a dozen other things. If I used the worker myself, could I have generated more than 1 VP for myself? Would it have an opportunity cost to do it? That is, I could see that I have limited actions, and I can use one of my actions to activate that worker and earn a VP plus get the result of his labor. Or I might use a different action with a different worker, and that worker would have been idle, anyway. If you have this situation, plus the case that these advanced workers are typically 'better' so I would be unlikely to leave them idle, then you have some decision tension (which is good for your game).

I assumed that I could refuse to lend him to you, but is that, in fact, the case? If he can conscript the worker, and only has to pay me a small VP for it, then it makes for a different type of tension. That could also be good, but not for a semi-co-op game.

I could see this working in a worker placement game with some special workers, but the cost would have to be variable depending on when you grab my worker. If in the first round of placement, when possibly I haven't even had a chance yet to use him, it should cost a lot of points. In later rounds, when I have already placed some workers so I obviously passed on an opportunity to place him, it should cost less.