I feel like Metamorph wasn't perfect either.
The default uses a Spear, which has a damage increase from Finesse. However, the stat Scaling for Tentacle Lash is exclusively Strength.
The other Metamoprh skills either have no Stat scaling, or scale off of weapon.
If the Metamorph were using a 2H Str weapon, all their abilities would scale with Str.
Therefore, I think changing the default weapon to a Str weapon or changing the scaling on Tentacle Lash to Finesse would cause this template to make more sense.