There are actually plenty of examples. Just named several off the top of my head.
One player's injury history doesn't prove anything. Sample case of one is just that, one case. Doesn't prove anything.
Last time I checked Gotsis and Attaochu played the whole year at similar weight-difference match-ups. So did many others in previous years or for other teams.
Last year's all-ACC defense:
DE - Vic Beasley, Clemson, 6-3, 225, Jr-R.., Adairsville, Ga. (161)
DE - Kareem Martin, North Carolina, 6-6, 265, Sr., Roanoke Rapids, N.C. (159)
DT - Aaron Donald, Pitt, 6-0, 275, Sr., Pittsburgh, Pa. (171)
DT – Nikita Whitlock, Wake Forest, 5-11, 250, Sr.-R, Wylie, Texas (156)
Great...you picked the exception in a year where two guys were similar to Green. Look at the historical All-ACC teams and you will find 2013 was the exception in those cases...while you're at it, look at the "ALL" SEC, PAC-12, B1G, and Big12 teams. Then go look at historical All-American teams. You said there are plenty of examples so this exercise should be easy for you.
One players case does prove something since we're talking about that one player. You can agree or disagree, but his track record speaks for itself.
Really, this is getting silly. Green is either healthy or he's not. He has not been. Period. If you don't think playing undersized as a DT isn't a factor, then good for you. There's a reason why Coaches and NFL talent scouts don't go recruiting a bunch of 6'0 250 lb DTs out of high school, or draft 6'0 280 NTs out of college.