It's tough to tell 100% for sure, but I'd bet there 3 different bear total (the 2 together and the lone one is the same in the other 3 pics). That lone one is a really good bear. I'd put it right around 400-450, playing it safe. Looks very similar sized to the biggest spring bear I've arrowed, missed Boone by 1/8th. That one also had a shorter, stubbier body for his size. It may go higher, but it takes one monster of a spring bear to even hit 400 lbs. I can't remember the exact ave % bigger a bear is by fall, but I want to say 20-30% range.
The other 2 are small/younger bear.
One thing is for sure, if the bigger one steps out, you won't be questioning if you should shoot it. Judging bear, particularly from tree stands (for me at least), can be tough. I messed up and shot a 120-130 lbser, after passing multiple 200-250 lbsers over 3 days (all on video) and had convinced myself that the one I shot was bigger than them, and that was after I'd watched him come to the bait 5 times. When we followed the blood trail right to where he laid, my camera guy got in an argument with the guide that the one laying there wasn't the one I shot, and he was 100% deadly serious. In fact, they were starting to yell at each other, when I grabbed the bear, picked it up, turned it around and told my buddy, "Shut up. It's our bear. Now film the #$%$ing recovery." (would have been hilarious, if I wasn't feeling like the world's biggest jack wagon at the time).
That was my second bear (1st was around 250), and I'll never forget how foolish it made me feel. It taught me an invaluable lesson, though. If you question for a second if a bear is big, he's not.
Also, I've hunted them exclusively out of ground blinds after that. I found that angle to be much easier to judge size from, then when looking down on them (all the hair laying down/out made that one look MUCH wider than he really was and played with my head, where the long legs and narrow heads are easier for me to spot/stand out a lot more for me at ground level).
In either case, when you see a really big one, you immediately know. No questioning it for a split second.