It's also a little bit of a mentality thing past physical. DTs tend to be lined up close to the ball and the rush is more instant. You need to attack more, even when you're in a pass set. Interior line is more like a wrestling match.
The DE / OT game is more about patience. Let the DE come to you, interfere, redirect. It's like a boxing match where jabs help control your opponent.
A good example of the mentality impacting a player's best position, look at Mike Whale. He was a supplemental RD2 pick mostly because he was a college LT. And he kind of flopped for us at LT. He wanted to get into a fight and tended to lunge and otherwise get beat at tackle, even though he had all the physical tools to be at least a decent LT.
So he gets moved to guard. NOW, his attitude is an asset. He thrived at LG.
Make sense?