Heya BS. Aside from the fact that your not working along a set axis (something that poser is not alone in disliking), the difficulty you face is that each "finger" or "fan" is dependant upon two other parts in terms of hierarchy. The membrane parts ideally depend on their respective "fingers" and the next one over. The central hand can mean a third parent for one object. I've been working on different solutions for a while... so far the only workable solution (barely!) is some very elaborate morph targets for the whole wing. But maybe one of the savants has come up with a better idea... :) Drop me an e-mail, bud.