Trying to assassinate Musharaff was bad strategy on AQ's part. If they hadn't, Mush wouldn't be after them; he'd say they were in the "wild, lawless tribal areas" and he couldn't do anything about it.
...chicken or the egg. Why would Al Qaeda try to assassinate Musharaff??
I think Musharaff was already after them before the assassination attempt. Thus the assassination attempt.