Ooooohhh - That could be a problem.
Why can't they just be happy for Danger and let him go on his merry way.
Tough for Adelaide - if a guy makes up his mind to go you would think it'd be best to let him move on.
I don't think they would stand in their way for Danger, it's more looking after their own house for what could be a big trade period for them if they want to get some high quality talent, as well as recruit some SA young guns such as Aish or Scharenberg or both they need more currency.
For example if we look at the ladder position now, if they don't match they will get pick 13 for Danger and that's it.
If they match Geelong they will get Geelong's first pick which currently would be pick 9 (already better off) and most likely something else which could be a Motlop, or a second rounder and a decent steak knives like we got in Crisp.
So long story short, don't match they get pick 13.
If they do match they could get pick 9 + motlop. Or pick 9 plus second rounder, plus George-Horlin Smith (random name). They could go on to use that first pick for an Aish or Shaz, still have another first rounder, and an extra second rounder for the other one.