Except Thornton has 4 career sacks in 4 years and is known primarily for his run-stopping abilities.
But other than that, yeah sure he's completely and totally just a cheaper Suh.
The math from the stats I can find.
The difference between Hayden and Thornton is 1 sack and 12 pressures.
The difference between Suh and Crawford (torn rotator cuff) is 3 sacks and 28 pressures
With Thornton, you are making up ~40% of the difference between Suh and Crawford who
tore his rotator cuff in game 2.
That gap may narrow with a healthy Crawford so one could 'expect' 50-60%.
Stats can vary with in different systems, but Thornton takes a double team and generated 60% of the stats Crawford did.
Hidden in the stats - Thornton probably got double teamed reasonably often but Hayden probably never did.
Thornton cost $4 million - seems like a cost-effective way to upgrade the DL.
Would I prefer Olivier Vernon with his 81 pressures and 7.5 sacks?
Of course, but he costs $20 million.
Thornton in 2014 when he was not injured: 739 snaps, 4 penalties,
1 sack, 2 QB hits, 17 QB hurries, 2 batted passes, 48 tackles, 10 assisted, 7 missed tackles, 36 stops, 1 forced fumble, 1 safety
Crawford pressures 2015 despite torn rotator cuff early in season:
3 sacks and 29 quarterback pressures
Hayden pressures 2015: 5
Suh pressures 2015:
6 sacks and 57 pressures