Then why have a spell that claims to do just that?
Honestly even with the suggested change it wouldn't make them useful in combat it would just give them a chance to actually hit the target.
However I've grown tired of answering your questions without you answering mine so until you do I'll just stop worrying about it. More specifically if you have some point you want to make state it please.
Oh as an aside even a base 10 strength wizard could have more than a 20strength without doing much in the way of work... much more if he worked at it even a little.