I just don't think you plan your entire OL around a guy who might only be here for two more years and who took 3 years to become even someone you can put on the field. He's turned into a good run blocker, but he still has major struggles as a pass protector that would force whoever the OC is to keep TEs and RBs in to chip on his side or outright stay in the help him block. It's hard to have dynamic pass attack when you have to give that much help to your RT in pass protection. In addition, I think it hurt Ruiz's performance because he had to help Penning and Ruiz doesn't have the level of skill to pull that off without his own assignment suffering.
And what the stats miss is that he was that bad as a pass blocker despite all the help he got. And I'm not just going by the pressure stats. I'm going about what I saw and he's still not what you need in pass protection. Maybe he gets better, but I don't think you can count on that or make plans based on that.
So, IMO, you don't build anything around him and where he fits should be an afterthought when fixing the OL. If Penning somehow take a leap as a pass blocker and wins the RT job then fine put Campbell at LG, but I wouldn't make any plans based on needing to find a spot for Penning or trying to keep Penning comfortable. He's going to be a 4th year player you have to either be able to take the training wheels off or be ready to move on at that point.
But, I'd leave all that up to the next HC. If he thinks he can work with Penning, fine, but I wouldn't eliminate the possibility of taking an OT if the value is there even if it meant moving Penning to Guard or sitting him on the bench.