Based on what's being said, I think NFL teams are making multiple plans as the NFL STILL doesn't have their plan together on what teams are and aren't allowed to do... so coaches are getting upset because they can't make firm plans until the NFL does that. Also considering the NFL usually announces something, and there are multiple different interpretations of what they're allowed to do, the NFL is already behind in explaining what's allowed.
Though what the Players Union wants sounds pretty clear, they want rosters to have a max of 80 players, and groups of no more than 20 players to be in any one spot at the same time, want them to be able to sleep at home (or at least not be mandatory hotels).
Which kind of sucks for the last 10 players whom think they're going to training camp but aren't... also I don't know if you can do groups of exactly 20. But you can certainly break the groups down (though I'm not quite sure what to do with the QBs)
How I think I'd break groups down into about 20 per group.
Based on current 90 man roster... 10 would have to be released to get to 80 man they suggested.
G1: Interior OL (10) & DL (8): 18 players
G2: OT (7) & OLBers (10): 17 players
G3: RBs (7) & FB (2) & ILBers (6): 15 players
G4: TEs (6) & S (7): 13 players
G5: QBs (4) & WRs (10), & CBs (10): 24 players
G6: STs only (3)
The biggest problem is timing and coaches, as only one group in one area at any one time. And do you have enough coaches where they don't have to go between groups, and can the coaches in the different groups can't be in the same area either. And do you have to clean the locker room after each group? Which is why some teams might be wanting to work in an area with multiple locker rooms.
G1 + G5 + G6 = 45 players one locker room, and G2 + G3 + G4 get the other. (or maybe just tell the STers to use Brett Favre's old side locker room area.... they're small enough group, maybe they can?)
Also problem with versatile players, like do you want to put RB Ervin with the RBs or WRs, as it seemed to me he was being used more like a decoy speed WR than a RB towards the end of the season. And might they want to try some of the OGs (Turner/Runyan) at OT.
Just throwing some ideas out there.