Argentina is not going to get strike-fighter aircraft that can mount an increased threat to the Falklands because (1) they can't afford to buy them, (2) they can't afford to maintain them and (3) most people won't provide them.
1. They won't be buying them - the story states that Russia would lease them.
2. They wouldn't have to maintain them - I'd imagine that support would be included in any leasing arrangement.
3.
Most people won't have to provide them, only Russia.
Having said that, I do agree that a strike aircraft such as the Su-24 does not really fit in with Argentina's requirements for an air defence fighter.