just because you want to think long on what skill to use doesn't mean they should have long GCD :)
having no GCD would mean skill spam, and you'd run out of TP right away, then only AA anyways. so the more you think about what to use, the longer your TP last. Either way i dont see why it would take so long to pick what to use ...it would be annoying to wait more than 4 sec to use whatever skill.
ofc there'll be skills with longer than 4sec cd. would be silly if you could use flare or whatever every 4 seconds.
