The federation - Picard - was heavily involved in electing Gowron to the high council
Uh, no, not really. Klingons are not *elected* to the council, they are *given* roles on it. The Chancellor can give a seat on the council to anyone he wants, for any reason, at any time; the Federation has never had anything to do with that.
As for Gowron, the Federation did not guarantee him the chancellorship, or have anything to do in selecting him. One individual - Picard - served as Arbiter of the succession. And that was only because K'mpec, the previous chancellor, told him to. Everything Picard did was according to Klingon law and tradition. Even Worf, in killing Duras, did so according to that same tradition (in that case, a revenge killing).