Our last mystery Commando artist is possibly a South American rather than Spanish. My research uncovered two artists named Roux. The first is Raul Roux, who is famous in Argentina as a comic strip artist who worked on El Tony—Argentina's first comic magazine—way back in 1922. His last comic appeared in 1949, which I think puts him out of the picture as far as contributing to Commando in 1964.
The second is Guglielmo Roux, the son of Raul, born in Bueno Aires in 1929. He worked as a decorator and restorer in Rome before returning to Argentina to teach. In the early 1960s he also drew comicsfor various magazines, later concentrating on painting and illustration. He is, to my mind, a solid candidate to have drawn the two titles listed below.
However, I might be barking up the wrong tree, so if anyone recognises Roux, please let me know.
Green for Danger (Commando 145, Dec 1964)