Think you're missing the point, the contention was that Castagna is better at ground level which doesn't stack up with reality, Higgins has had 21 stoppage clearances to Castagna's 5 (this stat excludes time in centre square). The fact he has had similar score involvements & only 7 fewer goals shows the added value he brings to the team. Tackles inside 50 also comparable, so pressure not in question.
But as far as the AFL benchmark is concerned, a fit Toby Greene would enter the conversation, Robbie Gray provided his forward split was favourable, a reinvented Luke Parker perhaps, Luke Breust another who offers infinitely more. These blokes kick double the goals, take just as many contested marks & get their hands on the ball twice as much. Does Castagna have the arsenal to reach these heights? I have my doubts but I'd like to see him at least replicate the form he showed in the opening half dozen matches. That was perfectly acceptable for a potential premiership player.
The extent to which he's fallen off the perch is troubling. 2 contested marks, 4 goals 9 behinds & a few out of bounds on the full, only 4 goal assists. The myth that he's a CHF surely needs reassessment.
Please don't bring up the halving of the contest line, that's lame. Hanley repeatedly ran off George as have a few others over the course of the season. The notion that he's playing on Michael Hurley or Jeremy McGovern is more mythical revisionism.