Sounds like you just want to be patted on the back and say you're right.
Going from a position of 'Do anything at any cost and sell the farm' is a horrible negotiating position to take. There is no way I'd want a GM to go into a situation like this and just throw whatever at it to get it done. If I'm the Raiders and I sense desperation, I'm pounding that GM. 'Hey, we want 5 1st round picks and Khalil wants the rest of your cap. Sounds great, sign me up! Oh wait.. 5 1st rounders, we meant 6.
Presumably the Packers took their shot and didn't work out. IMHO 3 teams that were interested still were better positioned from projected draft pick quality and cap availability due to cheap QB contracts so, the Packers were not in a position of strength from a draft capital standpoint. Another brutal truth is that maybe Mack wanted another 10M to play in GB instead of Chicago or NY. (Trade for him.. still have to sign him)
Now, if the Packers went in and say only offered a 3rd? Well.. shame on them. If they went in offering 2 1st knowing what they would have to outlay in cash and cap space well.. honestly, not much more you can do. 3 1st would have been too rich IMHO. And given I think there is one trade with 3 1st round picks given up (Walker), assuming the rest of the league agrees.