The comparison is that all of the Packer offensive linemen, save for centers, are 6-4 (or up to 6-6 for Datko). They all have the height to play tackle. Newhouse has longer arms than Bulaga. Either measurables make for a fine tackle.
No one has presented a reason why Newhouse would be better at guard. What is it? Size? Agility? Just citing the pre-draft write up is meaningless. If those actually meant something, 'Matthews is just an okay outside linebacker who would probably best be served moving to an inside position.'
You are the one who listed size not me. I duly pointed out that it isn't size because of Lang who at the same size plays guard.
Here is what James Campen said about Newhouse back in 2011 in an article on JS Online:
"OL coach James Campen on OL Marshall Newhouse
(Is he a guard or a tackle) Ah, he’ll play both.
(Was versatility a factor) Just the fact he graded out very well, was productive, has good length, good size, a very intelligent football player, does an excellent job picking up pressures, twists, you can see that, it’s pretty evident on film. Very good person, too, as well.
(What would make you think you could use him at guard) Well, I think he’s 6-3 ½, he has good measurables, very quick. I think with a guy like that he’ll give you some flexibility. He’s very smart. I’m not saying he’s not going to be a tackle, I’m not saying he’s going to be a guard, but I think we’ll look at him as we do all of our linemen where the best fit is.
(Is his body type conducive to guard) I think if you’re putting him in a box, I would say yeah. But again, you’re going to play your best players and wherever they fit, they fit."
So there is plenty of evidence he could perform well at guard.
I would also like you to provide a link to him making the team in 2010 because he failed at guard and only made the team on a tackle basis. Clearly as late as 2011 Campen was unsure of his position...and still might be.