Polymorph is not a magical skilltree, it is a physical skilltree at core.
combat-wise, sure. but it has uses for each class, both in terms of skill and the fact that it grants +attribute. you could say the same for huntsman, since high ground damage boost helps mages too, but polymorph feels like a more well-rounded tree for any class to dabble into
it also just depends on preference; tactical retreat gives you haste and is 1ap, spread your wings + flight is 2ap and doesn't haste you but allows you to reposition several turns in a row. it's a trade off, i think both are good
