Sr Velasco I envy you your group. As aggressive as my little newt is, and mostly, as ignorant and new as I am to amphibians, I would only add others with great attention and trepidation and the close advice of an expert, based on what I've read and seen so far. I haven't any idea how these newts socialise, how to sex them, or how to set up the right ratio of male to female, et-endless-cetera.
I find it very hard to resist anthropomorphizing. I've kept fish and I've kept lizards, and Oscar's cichlids are the only other cold blooded critter I've ever seen with so much, er, 'natural personality'.
To own a small group of them must be a real gas. Good for you!