How about an MVP-like statistic meaning cubers who made a difference, causing teams to do really well?
Like average rank of the teams they're included in. Faz for example is in 229 of the 241 teams, so his team rank average will be around 120. Przemysław Kaleta on the other hand is only in 17 teams and they're almost exclusively top teams (I'd say thanks to him) so his average team rank is around 15-20, I think. Jakub Wolniewicz is even on just a single team, which is ranked #2 right now, so that's also his average team rank, and I think he'd lead this statistic.
Or: For each cuber, replace them with "the average cuber" and see how that changes the rankings of their teams. Negated sum of differences might be good. Here I think Przemysław Kaleta might win, as without him, his 17 teams would be much worse off. I'm rather uncertain about this one, though. Rami would be very good as well, as his 11 teams are spread much more, so their ranks would really drop. In Przemysław Kaleta's case, his teams are close together and ahead of the pack, so they might not drop below many other teams. This could be a really interesting statistic.
