One thing I didn't see here was Smith has been a really nice downfield blocker. Something we know the staff stresses for WR. It may not explain all but that is a pretty good assumption based on what we see on the field.
Scheel is getting more plays each week. Just hasn't been targeted and against NDSU there were only what 24 or 25 passing plays with Kittle getting a ton of those targets. I would bet you start seeing more production out of him soon.