As far as the original question goes, the key restriction you missed is the HD limit. You can never take the form of a standard Storm Giant with polymorph.[/QUOTE]
I fully understood the HD limit on the polymorph spell. I should have been a little more clear in the original statement. I assumed way too much. I will try to explain myself further. The Storm Giant listed in the Monster Manual v3.5 is a 19HD Huge creature. IS IT POSSIBLE for their to exist a Storm Giant that could be anything other than an adault? Of course it would have a significantly lower ability in every category But, the question stands, is it feasible?? It would ultimately be up to the DM to allow such variations into the campaign.
By the rules laid down in the collection of books that is WotC, the spell was executed poorly with respect to the manner in which it was used.