The warden cannot swim

The warden cannot swim in liquids, somewhat nullifying its danger and disaster-like nature, supposedly urging escape rather than combat

What I expected to happen was...:
The warden would swim, or in some way attack the player more efficiently while swimming

What actually happened was...:
The warden was nearly stopped to a halt in both water and lava, rendering its attacks useless aside from the "sonic boom", which does pitiful damage if the player has any armour equipped.

Steps to Reproduce:
1. Get a warden, either by spawning one in naturally or with a command.
2. Lure it into a liquid.
3. Fight it in survival mode and watch it move at the speed of a snail.