Schwartzmann won already a ATP qualy last week in Chile and did win a Challenger in Bs As last year. He and Velotti are better ranked than Arguello, it´s logical. Andreozzi is injured.
Thanks for the information regarding Andreozzi as I didn't know he was injured. I know what you mean about Schwartzman's victory in Buenos Aires CH and his performance in ATP of Vina del Mar Q too.
Although I believe he have no talents at all. He has a big fighting spirit but with his height and resources I don't think he has any potential in the pro tour. Inspite of that CH victory I think the guy has zero potential (of course I can be provedto be wrong). On the other hand Arguello has all the tecnical resources to be a potential top 50 player as soon as he can be emotionally quite more stable.
Velotti seemed to make the jump some years ago and has a lot of resources to be a quite good clay court player (could be on hard courts too) but he remains stucked on where I found him two years ago. Zero progresses on tactical and physical issues which should be the strenght of the kind of game he propose. Grab him a look at ATP Buenos Aires and you find that.