Let's also remember that anyone who lined up at RT struggled last year, and part of the reason was the guard playing beside him.
Pettitti has definitely had a better situation this year with Rivera beside him...can you imagine getting advice or line calls or reminders from Gurode last season?
Tucker will perform better on the left side than the right simply because he has a veteran beside him who doesn't make a ton of his own mental mistakes. LA will give him reminders and advice, and if need be, a "Cortez-like punch to the face"...haha.
Tucker is a big question mark right now, but I think he'll make fewer mistakes and get more help on the left side than he ever did on the right side.