On a normal day, there won't even be a competition here. Argentina would have gone for a western fighter.
However since you are our adversary and we do have alot of influence and technological reach, we have already prevented Argentina from acquiring any Western fighter jet, in fact Argentina can't even buy fighters from non western sources (apart from China and Russia) since we still have influence and technological reach over almost every other major non western arms producing country on earth. Reason Argentina couldn't get south Korean T-50 fighters it earlier wanted. And of course , there's no way any western country will go against us by selling their fighters to Argentina.
So Argentina's only choice is Fighter's from Russia and China . I will say Russia has a higher chance of getting this deal though for obvious reasons.