Managers are typically excluded from being members of a worker's union. Also, the role of a union rep is very different from the role of a manager.

> And said extra managers are strictly interested in the good of the union.

Since they are democratically elected, they are interested in the good of their constituents. If you don't think your union rep has your best interests at heart, you can choose another one at the next election. If you don't like your manager, you can quit.

Supposedly that's the case for politicians as well, and we all know how well that works out.

Also I think you misunderstood my previous comment. I was referring to the union people as "managers" in quotes. As they're create an extra layer of go-between between us and the managers.