Huge difference between "a guy who will play in the NFL" and an "elite talent"... Julius Jones vs Ladanian Tomlinson, as one example.
The only member of the offensive line that has shown his potentially elite talent (still needs to get much more consistent) is Ronnie Stanley. McGlinchey is very Sam Young like. He has the frame, but now he needs to develop his strength and technique before he's close to being "elite". Nick Martin is solid, but not "elite". Steve Elmer could be very good, but I don't see Zack Martin in him. Do you? Quenton Nelson is the biggest question mark regarding his ability to be "elite", because we've yet to see him play.
In my mind, being "elite" has several tangible caveats (excluding factors such as luck and health due to their unpredictability):
1. Talent: encompasses the physical tools needed to be successful. To a degree you have it, or you don't.
2. Consistency: this factors in attention to detail, coaching, determination to be elite over a period of time and steady improvement vs stagnation.
3. Work Ethic: the "elite" guys NEED to be successful. It's all they know. They'll do what it takes to ensure their talent level is maximized, and often, their effort will surpass even their talent level.
Those are just a couple examples. "Building" an "elite" athlete is so much more than just talent meets opportunity. There are a variety of factors the play a part, IMO.