Oh, I see. Well, if it has to be the one being president when WW2 started then there's no choice. But I see there's a mod about WW1 too. The president when that one started was Roque Sáenz Peña, who was also much more important than Roberto Ortiz for Argentinian history.
However, if you are only looking for any rulers close the two WW, then I would stay with Yrigoyen for the first one and Peron for the second one, that way you would also have the two main parties that ruled Argentina in the 20th century. Oh, and about the traits, Peron HAS to be charismatic, it was his main thing in real history, so that definitely needs a change too. I would give charismatic/industrious to Peron and financial/organized to Yrigoyen (and if you are using Sáenz Peña... Maybe Organized and Philosophical, to represent his main contribution to Argentinian history by improving the suffrage law).
Will keep an eye on this thread if the mod is being re-done. It looked really good.