i keep 5 dogs, 3 in 1 yard and 2 in another yard, i have 2 yards as some can not be trusted wen i am not around. i do keep lizards, dragons and pythons in pairs and groups. they have been kept together for years, i am aware of the risks and have spare enclosures to separate them if need be. and in all these years i have kept reptiles together i have never lost a reptile or had one lose any limbs. i have attempted to put certain reptiles in pairs but they have shown agrestion and were removed straight away, i have a coastal that even in breeding season attacks every female i put him with and they are 100% female, he is housed on his own and will be for the rest of his life. at the end of the day its personal choice, and should only be done if you can read your reptiles body language so you know if they are gonna attack or not wen introducing. and watch their behaviour and interaction even years later as they can change.