Hello,
According to early planning, to attack warships the FAS (Fuerza Aérea Sur - South Air Force Command) recommended Zuni (127mm) rockets and 500lb (and heavier) bombs. To attack landing craft, the recommendation is to employ up to 250lb bombs and FFAR (70mm)rockets.
However, just before ops starting, the FAS realized the bombs gives more bang for the buck, so all antiship missions were armed with bombs (from 500lb and up to 1000lb).
The MB339 Macchi which attacked Argonaut on May 21st, 1982, was configured for armed recon (with rockets and gun pods). In fact, when landed the pilot (Lt. Crippa) asked for a bomb load for a re-run, but the higher echelon rejected another sortie (because the attack waves were en route from the mainland).
Regards!