I could get conditioning issues, but we are talking about vets with near or over 10 years experience with Peters and Fisher. They won't need that long to get the playbook down. Hate to over simplify it, but it's OL play, not a WR or TE or RB learning a playbook. It's either you run block or pass block. Certain blocking assignments are called out by Biadasz based off what the defense is showing presnap.
And we are talking about Tyler Smith, a raw LT from Tulsa who had issues last year with holding. He didn't get any snaps in pads at Left Tackle this training camp. I much rather roll with a 20 year vet with 1 week of practice than a rookie with maybe 2 weeks of practice at the position.