Hard to tell by pics esp with winter fuzziness and it's best hands on but-
Bailey 6/6.5 with a big hay belly. Diet and work on that belly. I think the belly makes him look heavier then he is. I almost thought HE was pregnant..
Dime 6.5 I actually feel he is the heavier of the two. He has a more stocky/round build that hides it far better. Definitely a diet here.
I think I'd want them both at 5, maybe 4.5 for Dime.
Actually don't think the Arab is that bad (assume the pic with the child is older?). Maybe a 4. I'd want him 4.5 then work on muscle tone and building up his topline. Nice horse he reminds me of my guy :)