Yeah. It would be weird if you hit someone with a combo move, say like Giga Drain + Tackle, and it hit for ... 16, but you only got 5 health back. Since you caused damage and a part of that was with an attribute to heal, you get more health back.
Its like if you hyped up your attack, your healing properties would rise since you inflicted more damage.
And there's the matter of the defense drops of Yaj as well. Woulda been less :O. Maybe