For one leo/fatty you should have a minimum of 2ft x 1ft floor area.
Majority of reptiles have no need or want of company. To them it's competition for territory, food, hides, warmth, mates, lay spots etc. They can often live together without showing much interest in each other or 'cuddling', but more often than not this results in aggression or at the very least dominance. If you do house more than one together, there will be one dominant individual and a subordinate. Subordinate gets bullied, that's the only way one will maintain dominance. This often starts with little gestures that we would never notice (looks, body language etc), and can quickly escalate into fights.