I've seen many matches were Velotti played great and he's got more hype going on than most of the other young argentine players coming up but, yes, in a way i agree. He fights hard, has some touch and solid groundstrokes but i belive size will be a huge disadvantage for him as he progresses in his career. He's very short, serve is attackable and lacks power overall. I mean, Schwartzman is even shorter and smaller but generates way more pace in all of his shots, to name an example out of that group. Arguello has the most potential by far IMO.
It's an exciting crop of players, though. I hope they can all push eachother on, and keep improving.
I've always rated Trungelliti, not as highly as the likes of Bagnis, Arguello and Velotti, but he's certainly a handy player. Anything can happen at more advanced ages. Just look at Alund, he's 27 I think, on his way to the top 100 after a lot of obscurity. I'm not saying he'll go any higher, I sure hope not, but there are ways to improve right into your twenties.