Elam's problem was that when he got tired, he tended to stand up out of his stance. This enabled an offensive lineman to take him on one on one. That in turn enabled the guard to brush off double teaming Elam and block the linebacker. This was one of our problems against the run last year once Lewis went down.
We will see if he can participate in several plays in a row without losing his wind this season.
What you were seeing, more often than not, was a zone or a "combo" block, not a true double team block. The fact is most offenses today do not use a "true" double team block anymore.
Back in the "power football" days (60s and 70s), yes, you would often see a double team on a NG by the C and play side OG usually in an effort to get the NT off the LOS and become a hinderance to backside pursuit. FB leads through on the LB and you have the classic isolation play.
Today's zone blocking schemes are more about wider splits, footwork and sealing DLs off to create "running lanes" rather than trying to knock them off the LOS and create a specific point of attack "hole". Spread sets move some of the second level defenders out and the deeper handoff (i.e., shotgun handoff or "stretch" handoff from under center) allow the RB to "find a lane" rather than simply plunge into the 4 hole or whatever.
Aside from "conditioning" I thought Elam's other problems were at least somewhat related to his enormous girth. He now should be able to get into a better stance and show more explosion from his stance. There is a common misconception about "holding your gap" (or "gaps" if playing an even technique, i.e., 0, 2 or 4)
DLs, regardless of size, are not taught to "catch a block"; they must explode into the blocker and "deliver the blow" to gain a momentum advantage at the LOS. I guess what I am trying to say is you want to hold your gap BUT you want to "move" the LOS into the offensive backfield. Doing so essentially blows up ANY run play between the OTs. When that happens on a regular basis you will have pretty much stopped any run game.
Peace