Tentacle lash and bull horns are the only damaging spells from poly right now, the others are all utility. My main point is how useless dual wield is because of your ability to get the same benefit from extra points in finesse.
And thats the problem, polymorph gives you a huge amount of utility, not just in its spells, but in the weapon choices you have.
"what would be best for this fight? oh Ill use a bow, because I dont want to get close to X enemy. This fight ill use a rapier and shield so I have more armor stats without losing out on a lot of damage because all my points are in finesse anyway. This fight ill use the invisibility skill and dual wield to try and quickly take out this priority target."
You can do all this without losing out on damage, whereas if I had put my points into say ranged, I would be stuck, it would be "Well dual wield would be better for this fight, but if I dont have my bow equipped I lose 40% damage" Which is not the case when you only level Poly and put points in Finesse.