When I watched his college games on video, he looked like he deserved all those holding calls and a bunch more, at least by NFL standards. He allows defenders to get into his chest a lot which leads to the grabbing and those wrestling moves. That will get called in the NFL. Maybe playing guard where a DT is coming right at him on every play he won't need to hold so much. But NFL DTs are pretty quick too, maybe as quick as most college DEs. The Cowboys don't seem to be concerned so we'll see what happens. Trevor Penning had 16 penalties his last season in college too. I suspect there are others who got flagged too much as well. I think Smith has the reputation because of his poor technique.
My concern is him having to improve his technique while learning to play inside. He could struggle early. We could see something like what Andrew Thomas did with the Giants. He was pretty loose his rookie season but got better his second year. The adjustment to NFL speed and power takes some guys a year or two to figure out.