Star Alliance generally has the best coverage in Asia, but you'll probably end up flying on LH a lot, plus LX for those few destinations they serve direct out of ZRH. The problem is the location of the hubs of the Asian airlines: flying SQ to most anywhere except SIN (and Indonesia), TG to anywhere except BKK, NH to anywhere except Japan and CA to anywhere except PVG/PEK would in practice mean backtracking or flying in the wrong direction and thus increase flight time to an unacceptable extent.