What European Parliament Parties would politicians and parties outside of the E.U affiliate with?

[Former President tack50]

Republicans: Mostly ID, with some ECR elements
Democrats: Mostly RE, with some S&D elements
Greens: Greens/EFA
Libertarian: EPP? (I'm genuinely unsure on this one)

We do not need to speculate for the Republicans actually, since they have some sort of "cooperation agreement" (whatever that means) with ECR.

Because of their different history compared to European socdem parties; the Dems would indeed be in RE (much like how the Canadian Liberals would)

The Greens would be in the G-EFA, no surprise there

The Libertarians, as weird as it sounds, would also probably be in the same group as the Democrats (RE) since it's the closest to them.

[Former President tack50]

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