+1. Summed up nicely.Bit of an apples to oranges comparison. Walker is physically what you want for a T, he's that talented. Bakhtiari was an undersized guy with crazy determination and flawless technique. Bakh in his rookie year was better than Walker has been as a first year starter. Walker gets a little lazy with his technique and for a guy with his talents should be a better run blocker. He might improve (I have concerns about the OL coaching) and if he does they have a very cheap contract for a starting NFL LT. I would not be shocked if they draft a OT early, mostly because I think they want more competition and they aren't likely to have Njiman and Bakhtiari on the roster, which impacts their depth and quality.
Runyan has almost guaranteed himself a ticket out of town with how he's played the last two seasons, which is unfortunate. He started out really good (Newman wasn't bad as a rookie; this regression being the reason I worry about the OL coaching) and has regressed. Maybe he has an injury or RG is the wrong position for him, but there are times he looks fine and others where he looks like he doesn't know how to play football at all. Myers too, but I think they let that contract ride out another year and expire.
The tl;dr is do not be shocked if invest heavily in OL via draft/FA. They have talent on the roster but it could be a LOT better.
Consider this: why were they able to run the ball last year but not this year. (Before you say it's Aaron Jones injuries, recall that Aaron Jones is having a very down year statistically.) They can still pass block ok but this OL has gone from very good to very mediocre, primarily in run game.