I love my vet, but she's the kind who would rather see them a smidge under weight. Rather than over. And I have always been the opposite. And for blanketing. My family has always been this way. Since the horses were babies. And we never have hairy horses.
Agree with Alex. Your colt looks OK but the others are a bit too fat. Yes, many people 'like' to have plump horses, but there is a very good reason your vet holds a different opinion. Health. IMO that should definitely come before your personal preferences. It's one thing if you overeat yourself, you're creating your own problem, but you are in charge of your horse's welfare.
As with humans, it's not healthy to remain overweight & leads to a number of(some incurable) health problems. Unlike humans, one of the common ones - laminitis - makes a horse lame & can do extremely serious damage to their feet. Like humans, other animals can all afford to put on extra weight at times & not necessarily suffer, but *retaining* 'good condition' long term without regular 'hard seasons' to use up the fat stores causes metabolic problems such as insulin resistance/type 2 diabetes. This is not considered curable & is a LOT easier to avoid than having to manage once they get it.
As for rugging, I think there's more you should consider than a bit extra hair to deal with. I don't think short term rugging in appropriate situations is necessarily at all bad, but also agree with Alex that 60o is not what I'd call at all necessary - perhaps when it gets below 0 if they haven't acclimatised or grown a decent coat or such. There are also health considerations that are at the root of my attitude on that too. So it's well worth reconsidering changing your 'likes' that aren't in your horse's best interests.