The thinking of Cooper to the Bears is that Kromer will be implementing, if not a full blown Zone Blocking Scheme, at least elements of it. And Cooper's skill set is ideally suited for ZBS (which typically doesn't require 330-lb road graders on the interior). Which #1 is why some people think he will fall (he simply won't be a good fit for every team) and #2 why the Bears may jump on him if he does.
Cooper is also projected to have the ability to play C though I don't know if his college career included any time at that position. That may be a place he could get by at a slightly smaller size until he has the chance to bulk up for a year or two. His weight has been listed as everywhere from 295 to 310 so he may be a guy who hasn't really found his ideal "size" yet.