What they say and what they are thinking can be two different things and when they decided to let Cooper go and keep Gallup, they knew there was a possibility he would not be 100% for a significant part of this season.
That is why I think the first pick is WR and Booger thinks he's being clever saying OL and will throw other teams, all hanging by a thread to see what the mighty Cowboys will do, off the trail.
I think he believes he can get an OL in the 2nd round that will be better than a WR in the 2nd. Gallup was a very good pick but he is still a #2. And I do not think they're sold on Lamb as a WR1.