I do not disagree with the above advice.
I am going to state what my experience was with keeping melleri in groups, 10 years ago.
Again, before I describe my experience with them, in the past, I more closely enforce the above recomendations, though I have no negative experience to justify the change, only a better understanding of better approaches, today.
I kept 1 male and several unsexed juveniles and 3 females. There were never any territorial disputes, fights, glaring at each other, only courting. They got along well in cages as large as 21' long, 6' wide, and 6' tall. They got outdoor 7'x7x7' cages, outdoors, all during warm months, and were split into 2 groups, each in there own cube. I think keeping a male and 2 females is fine, in a large, planted enclosure, with ample basking areas, UVB and hand feeding.
I don't think 2 males belong together.