I think we already have a deal with Rockliff, and have since the last off-season.
The gut feel I have with the Rockliff situation is that he's looking for a contract elsewhere that's enough of an improvement than the current offer from Brisbane, that would make it worthwhile moving his family. It makes sense that the current offer is less than his previous one given that when he signed the previous contract in 2014 (despite the rise in salary cap), he was equal 5th in the Brownlow the year before and was in All-Australian form in 2014.
There's no way Rockliff gets a big enough contract that nets Brisbane a band 1 compensation. I also think if Adelaide makes an offer that Rockliff accepts then it's unlikely Brisbane matches given Rockliff would likely accept the matched contract from Brisbane (because his family gets to stay, and he gets the bigger contract).