I'll take a guess for argentina, based on who i think they'd get along with better:
PRO would be in EPP
PS, GEN in PES
UCR either in PES or ALDE
CC-ARI in ALDE
The Left Front parties in PEL (assuming they overcome their instincts towards infighting and splintering)
As for the PJ and all it's minor satellite parties, i have no idea, is there a left wing equivalent of Identity and Democracy? If not, then the PJ would probably create one.
I suppose PJ could have been an ok fit for the old EFDD group, which was pretty much Movimento 5 Stelle + UKIP before they went insane + couple random parties.
These days M5S is part of the Non Inscrits groups, alongside the Catalan Junts, a couple nazi parties and a couple randos. So again maybe they can cobble up something consisting of PJ+M5S+Junts+randos
I can see traditional peronists hanging out with M5S, and the 90's PJ would definitely be best buddies with Forza Italia. But kirchnerists are harder to pin down.
If transplanted to Europe, i imagine they'd be eurosceptics and against NATO, probably backed by russia, critical of Fidesz and PiS for the anti-LGBT stuff, but otherwise very supportive of their style of government, their main company would be eastern european parties and fringe figures of the west like George Galloway, but they could maybe convince Podemos to join them (they have good relations IRL).
