I don't dispute that Trevor Ruhland was getting overpowered at the guard position at various times last year. He simply wasn't the ideal fit for the position, but at least he was a better fit than the younger players.
Center requires more brains than brawn. You have to understand the mechanics of the line, coordination, and be able to make adjustments on the fly, which is why you rarely ever see a younger player starting at center. For that matter, you'll see many failed experiments where a talented guard or tackle who has proven himself at that position, gets moved over to center, and has an absolutely rotten time trying to put it together.
In terms of strength, even if Ruhland isn't as strong as we would hope, he'll still have help from the bruisers at the guard position.
This has been the case for quite a while. I remember even back in 1990, Mike Heldt was probably 270 lbs on a good day, and that was after eating a 7 course meal. Most of those linemen were pushing 285-290 lbs easily, and were a lot stronger.
He was still the best option we had at center, though, since he had Mirko Jurkovich and Aaron Taylor at the guard positions. Dare I say, he did a very fine job that year, especially against a lot of those early round draft picks.
For that matter, even Lance Johnson at his 265 lbs did a nice job when filling in at center.
If Jeff Quinn can make sure that Ruhland can get the mental part of the center position down, then I feel pretty good about him. Trevor Ruhland is a pretty smart guy, and this may be the best position for him, and for the team.