Unless Adelaide have changed the way they structure their payments they won't be able to bid high enough to bother Collingwood.That is the key..I think you are right on the matching of bids that a deal does not have to happen on reading up on it..unless Grundy decides he wants to leave. Recalling the dangerfield situation, the crows apparently told Dangerfield and his management they would match any bid by Geelong to ensure a better trade was gained, unless the rules have changed, I suspect the same would apply to Grundy if he told Collingwood he was out at the end of next year (that collingwood can choose to match to ensure they get a better trade)
And this is why the crows would be wise to wait till next year and not burn pick 1 this year when they can get a top mid and maybe get Grundy next year - if there is even a skerrick of truth behind the 'reports'
With Dangerfield, we weren't (and aren't) paying him full market value so they Crows were able to threaten to match. We could have bid higher but that would have messed up our pay structure so the two clubs basically met in the middle, Adelaide got something (not full value) instead of nothing and we got to keep our payment structure. Also Dangerfield had given the Crows very good service over the years so the Crows were not of a mindset to scorch the earth with that one.