During that war Argentinian air force resorted to sending smaller number of planes against RN ships that allowed its air defences to operate better and provided larger degree of protection. So why didn't Argentinians use one larger raid that would overwhelm air defences and allow for better results? It doesn't seem that this was an issue of availability of planes, weapons (while Exocets were in short supply bombs don't seem to be) and pilots as they kept sending them up despite losses.
One of the big reasons for this was the range to the British Task Force. The Falklands were at extreme range for many Argentinian aircraft operating from the mainland, and the Task Force largely operated further east from the islands. To extend the range of the strike aircraft, in-air refuelling could be used. However, this was limited by the availability of tanker aircraft. The 1st Air Transport Group of the Argentinian Air Force (FAA) operated just two KC-130 Hercules tankers; these were the only tankers in the FAA. The KC-130 was not an ideal tanker aircraft, having a relatively small fuel capacity and relatively few hoses for aerial refuelling. This put a major limit on the number of aircraft that could be effectively operated on a strike. Four A-4 Skyhawks could be refuelled from a single KC-130, or two Super Etendards. The FAA operated more Mirages and Daggers than A-4s or Super Etendards, but these aircraft could not refuel in-flight - they could not effectively make strikes to the east of Falkland Sound. This further reduced the number of aircraft available to make strikes against the Task Force.
Another major reason was maintenance issues. Aircraft require a lot of maintaining to ensure that they can fly safely and fight effectively. The number of aircraft that are on a squadron's books does not necessarily equal the number that are ready to fly at that time; some of them might well be down for maintenance. To ensure that every one of a squadron's aircraft is ready to fly means slowing down the rate of sorties, which gives the enemy more time to prepare and rest. Maintenance problems could also strike in flight, which cut down the number of aircraft on 'maximum effort' strikes. On the 8th June 1982, the FAA attempted to carry out a major strike against British shipping around Port Pleasant, originally planned to consist of six Daggers and eight Skyhawks. One of the Daggers dropped out with a cracked windshield, while three of the Skyhawks were forced to turn back, one with oil pressure issues and two with icing in their refuelling probes.
A final problem was that the FAA (and Argentinian Navy) squadrons were widely spread between bases. Air bases only have so many parking spots, so much tankage for fuel and storage for munitions; they cannot easily be overloaded for long-term operations. The FAA had two squadrons of A-4s, one based at Rio Gallegos and one further north at San Julian. Each of these bases was also home to a squadron of fighters, with Mirages at Rio Gallegos and Daggers at San Julian. The Navy's Skyhawks initially operated from the carrier Veinticinco de Mayo, but later moved to the land base at Rio Grande, which was also home to 12 FAA Daggers and the Navy's four Super Etendards. This dispersal made it difficult for strikes to be effectively coordinated. Going back to the 8th June, the two groups of aircraft attacked independently. The Skyhawks were flying from Rio Gallegos, the Daggers from San Julian. The Daggers could not refuel in flight, were faster aircraft and were flying from a closer base, while the slower Skyhawks were further slowed by the need for in-flight refuelling. The Daggers therefore reached the islands and attacked first, making an unsuccessful attack on the British frigate Plymouth, while the Skyhawks made a later but much more effective strike against the landing ships Sir Galahad and Sir Tristram at Bluff Cove.