Hi @iveliart
If these groups are defined based on criteria like LOBs or any other, and they will be working on a set of projects dedicated to them but not to others - I would go with separate env for each for easier management, access, etc.
This will also ensure each group has its one license /bot waiting to use them, so, for example, 1 group does not consume others' licenses, blocking others' bots.
At the same time, you can have a shared env where you can have bots/flows not dedicated to the specific LOB.
So kind of both worlds.
I believe MS advised the same approach as above and has a whitepaper. You can look it up.