I wanted Semedo as our starting RB. I thought he was the best young fullback I had seen since Dani Alves. I have said it many times. But now that we signed Walker (a very good player in his own right) I didn't think we'd be going for Semedo any longer.
As for Denayer, I don't think Pep would give him the opportunity at RB. I wish I was wrong. But he'd need to go succeed somewhere else to get a fair chance here :(
We would definitely have scouted Semedo and no ones more likely to see the next Dani Alves than Pep, the guy who forced Barca to pay the €30m for a RB when everyone else (Juve,Liverpool,Chelsea) thought it was far too much for him.
I think this, like defensive midfield, is an areas where you just hope Pep knows best.