Support QampA Rules Dragons and Dungeons Daishains The Protector. says...
That's a fair question Dai, but Tazskan's hit points are low for a pure melee character.
Because he has the ability to cast, destructive energy, it has been easier, for him to use this. As opposed to receiving more damage, and possibly giving it in melee?
The rationale being, to cast offensive spells first. Wait until a stronger opponent is weaker, then go in as a Paladin, in melee. This, would be the case for dragon's, and powerful creatures.
But, against something like an Ogre, or a Cultist, etc. Then your correct. He should engage as a Paladin in melee with them. But, still a fair question to which I don't have a full answer yet. I know, I do seem to be using the Warlock abilities more of the time, in retrospect.
One thing, Cinder mentioned though, if Tazskan were to level up again the prudent choice would be Paladin over Warlock. To gain the extra attack, but that would be a Paladin style melee attack!