That is fucking stupid. Making design choices where one race is the flat out correct choice is wrong.
In this case, the correct way, would be to make each have unique advantages. Ogre, has blunt damage reduction presumably. more hp. And possibly a larger hitbox/collision to prevent targets from getting around him.
How can we balance that? well, no one would want actively engage the ogre directly. So he should have problems generating threat. halfling though?! kill that fucker! high threat generation. small size? 50% evade/miss. Maybe hes faster as well. 10% move speed. So this little guy can now move faster, generate threat faster, and avoid hits. he is much more effective at picking up attackers on allies, as well as grabbing aoe aggro.
And yeah. an ogre and halfling should need to spec and build their same class differently, due to those racial variances.
The key then is to also make sure all your content does not favor any one particularly too much. Having a race/class that is good at picking up adds, then having every single "boss" a pure tank and spank, destroys your class design, and puts it all right back on the one correct class/race choice.
this is the same problem we were talking about str/dps rogues. even if you put skill rogues int he game, if the entire game is built on dps=win. then building your rogue as anything but dps is wrong.