The Frost Tower was made to being parallel with the Gargoyle Tower which is fire and is weak with to frost. But that was a giant failure! Neither Tower was at all useful they finally made the Gargoyle Tower only useful if you got the horses and boost. And the Frost Tower was never close to fixed!
So this would make me use the frost Tower: First off allow the range perk to be upgraded. Second remove its weakness to fire if you look at the Frost Tower it’s a giant fire hose there’s no reason to have a weakness. The Frost Tower would be very strong but to ballance it deal minimal damage.