I think it defaults to Grundy sadly. The lowest price he has been since 2017, we know he can score well, has a great mid fueld around him, should go at 100 at least, other options are probably higher risk.
Grundy is a real hard one.
There's such a huge "got his contract and doesn't care" about him. Downward trend for 4 straight seasons to the point where his team gave him away. His starting average is his legitimate average from last year and now he's in a ruck share with the best ruckman in the league. This is a guy who's never been good when ruck sharing.
Really Grundy's "shining light" this year is he's such a terrible forward that we're all assuming he'll get the lion's share of the ruckwork but the reality is Gawn isn't a very good forward either and he's a much better ruckman.
Also worth noting that the list of ruckman who averaged 95+ while in a ruck share was Gawn last year and his ruck share was still dominant enough that his partner got FWD status this season. Best guys in genuine ruck shares were Marshall, OMc and and Goldy, and Goldy the pick of them at 93.
Grundy might be good, maybe the Pies basically paying to get rid of him will light a fire that hasn't been there since he got his contract and he comes out firing, maybe they Gawn has added significant forward skill and basically allows Grundy to ruck 70%+ but that's a lot of maybes for what is not a significant discount.
FWIW, I think most of this applies to Gawn also, wouldn't shock me if either were still the top ruck but I wouldn't back it at the same time.
For mine the top 5 rucks removing durability is English, Darcy, Marshall, NicNat and Witts but for the first 4 durability is an enormous factor that really can't be ignored. I think both Gawn and Grundy could be in that group and ROB is really just his midfield dragging him along from being capable also but his lack of ruck skill is definitely a worry and I'm not sold he has the midfield to do that and he's not really shown anything to suggest his ruckwork can improve, he can't jump and he's already big and strong so I'm just not sure he can add it, especially given he looks genuinely uncoordinated in all facets and that holds up with the tapwork.
Again, the rucks are a nightmare and I'm still yet to settle on anything that resembles certainty.
The fact NicNat is now one of the most durable ruck options sums up the complete lunacy of the position.