Yes they absolutely do because its voted by media. Surely everyone can agree that the bulk of the media today has little to no integrity. Do you really think 300 media members are putting in the time to study the best players at each position in depth enough to support their vote? Or they just vote on name brand? Personal bias? What other members are doing?
When Zack was young, all that was true. They kept saying it long after it became untrue.
Larry Allen is arguably the best OL to ever play the game. He is certainly on the very short list of players who could be considered. Zack is no where close to that argument. There are many who think that Eric was Larry's equal or better. That is a justifiable argument considering the level of players he whipped into submission. Sorry, but those guys are amongst the very best to ever lace them up in league history, not just Cowboys history.
Zack certainly has a place in the pecking order but he's clearly not at the top even in Cowboys lore.