The problem is that then Franklin doesn't have to accept the trade, so Hawthorn would be stuck with the 10 years and also having to offload some players to find the salary cap space.
Sydney cleverly generating another 'legitimate' loophole IMO.
Sydney just have him play for X years, back end load the deal as needed,
include the "major injury insurance" (Buddy gets paid out if he "breaks down" to quote Swans boss) then (this being the unwritten gentlemen's agreement part) Buddy 'retires' at a mutually acceptable time then signs on as an AC and highly visible club marketing person on coin that doesn't come out of the Cap. Cap dollars go back in the bucket, Buddy gets the coin he wants (as opposed to the headline number), Buddy gets to be where he wants to be, gets an after-footy career, and the Hawks can't possibly match the headline offer.
Sydney offer lot more than Buddy's bottom line, never end up paying it, which makes it impossible for Hawthorn to match the deal.
Of course Buddy could destroy things by walking away or whistleblowing, or a future administration could have a run in with him, or just an ethical or philosophical difference with the arrangement but what are those risks against (say) a flag and a GF appearance in the next 5 years. Look at the TV ratings for the three grand finals Sydney played in in the last decade. Very interesting if you're a potential sponsor.
Agree though - the AFL has the right to reject the deal if they think it might 'break' the Swans, based on what they have 'promised to pay', even if that is a bogus number. Limiting a contract offer to another club's RFA to 5 years closes the loophole somewhat but not entirely. Similar in structure to the pre-FA deals with Cornes+Brogan to GWS - offered AC roles after they retire 'again'. Though that situation exploited a different 'loophole' (if they retired the first time around with the intent of returning to AFL outside the draft).