Personally I don't think you can put DCE in the class of Thurston or Cronk on form over the last 5 years. Thurston and Cronk have shown they manage games and close them out, when the game is on the line they take control and play the percentages in a very Andrew Johns way. How often in recent years have we lamented our halves ability to position for a field goal or something similar?
Now I do think something that affects this is having 2 dominant halves, which we have had. So sometimes they can get crossed wires, whereas in recent years Cronk and Thurston know it's their job. This is something DCE will get better with going forward.
The comparison though on grand final wins I don't get. It's a team effort, and a half can't win comps without a solid team around them. Do we say Mitchell Pearce is a greater half than Thurston because he won a grand final at a younger age than Thurston? (As the starting half). Of course not.