It's easier to get a new o-line coach than to keep using high draft picks to upgrade the line...
Of course it is, but finding a OL coach who knows what he's doing may be even harder than finding young OL talent..
I disagree.
There are 15 good OL coaches in the NFL. There are not that many franchise LT's playing in the NFL. That is why Joe Thomas is looked at highly and I would not be dissapointed if he was picked.
With that said good o-line coaching makes everybody better not just one position.