As both of you mentioned (and I acknowledged) there are some unique cases. If I did roll great speed on a "mismatched" mod, it would probably end up on a character like NS zombie or Jawa Engineer or possibly Sith assassin - someone whose only stat that "really" matters is speed.
There are some other unique cases - especially now. Fives can benefit from offense and defense since he passes those on if he sacrifices himself. Or GR teams where health is always a good secondary. Droideka, who is best with very little speed, etc.