If I was City, and the PL came to me in these circumstances and said, yes we know we all signed up to this procedure but we want to tell the panel to have it all settled by the summer, is that OK? I would have told them to fuck off and, when they get there, to fuck off again and, if they did try it, we would take them to arbitration and the high court if necessary and lose another two years. I don't get the impression that the club are in much mood for compromise on this whole thing unless its on favourable terms.
Who knows? Maybe the PL tried to impose timing on the panel and that is exactly what the club said, and did .... (yes, I know I shouldn't have ....)