KSB can be kept in groups. There are species that shouldn't cohabit, can cohabit, and have to cohabit. Regarding BP, its best to keep them housed individually, which is why many people say not to cohabit. However, species like rosy and Kenyan sand boas can be kept together.
I would imagine one male to several females. They're not very large snakes so you can probably fit a decent number in a 40 gallon. More than one male may fight for the females, so its probably best just to have a single male.
The issue with keeping more than a few snakes together is that feeding them might be a problem. Its best to feed in the enclosure. But with so many snakes, it sounds difficult to do.
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