Well its really up to you and the arguement goes on and on with this issue. Here are some facts about why you shouldn't.
1. Cannabilism, rare...but has happened as shown in many a photo.
2. Passing if sickness/disease. If one of your babies gets something you automatically have three vet trips, not one. If someone has odd crap you can't tell who it is either.
3. Early mating. I can't say these hatchlings are right now in danger of this. But soon enough they will be and it could be too early for the female which can mean serious condition, or even prove to be fatal in some cases.
I would give you facts on why you should house them together but there are none. I can't think of one viable true reason to house snakes together. Use this info just to form your own opinion because like I said many don't agree with me and think they live together fine, although there is no reason for it. I understand your concerns over heating issues, and you can check into heattape which is used to heat any number of rubbermaids at the same time.
All in MHO
bmm