We'll have a better idea what Ted was thinking when we see him in camp getting reps. McGinn and every other Packer blogger had Clark as the need pick (or someone was leaking). And they ALL see him taking Raji's spot at NT.
From that perspective, you can see the Packers having him as their highest ranked at a position of need.
Nutz and some other write ups see him as more versatile, though he is not as tall as most 5 techs. If he gets reps all over the line, might mean the plan for Raji's replacement isn't set in stone and they just needed a body.
If that's the case, then you have to think they just liked him more than any other interior lineman.