I've been doing a leftist Mexico playthrough. I like to send 2 infantry divisions to fight in Spain, and I can help win it for the Republic as Mexico fairly reliably. I know if the USSR does not seize the Spanish gold reserves, it can puppet Spain more easily. As Mexico, I seize the gold because revolutionary Lazaro Cardenas wants that conquistador gold back (also because Mexico's industry is really mediocre). If you don't seize the reserves, can you also puppet Spain as Mexico? Or would it just mean the Soviets end up puppeting Spain? Or does it do nothing except save you some political power?