Multiple JA procers compounds the advantage JA procs have over others and I would put magic lower than 5% and yeah I would say WS procs are probably more like 20%. Sometimes when I have no other option I will try to magic proc a mob until a JA or WS mob pops and it has worked 3 times in god knows how many tries. That was spamming cheap spells not just waiting on dia timers. They could do something with spells to limit our ability to spam anything we had and increase the proc rate drastically and that would be fine. Maybe base a spells chance of procing on it's casting time.