I found an interesting article about the effectiveness of a conscript Army published by Alejandro L. Corbacho, Department of Political Science, Universidad del CEMA, Buenos Aires, Argentina. I have added it to my links and also included the section relative to Tumbledown below.
Mount Tumbledown: Preparation for Battle
On April 8th, the commanding officer of the 5th Marine Battalion, Commander Carlos Robacio, received orders to go to the Malvinas. Until April 12th, personnel and equipment arrived at Puerto Argentino. Once the unit was totally in place, the High Command ordered its members to prepare defensive positions around the capital. More precisely, the 5th Marine Battalion was responsible for Mount Tumbledown, Mount William, and Sapper Hill. The battalion had to cover a perimeter of 16 kilometers. To accomplish this, the battalion had a total force of 703 men. All conscripts, the Marines were from the class 1962 or older, and no new conscripts (class of 1963) were sent to the islands. The battalion was far from complete, since only the rifle companies, the headquarters unit, and a few logistical units entered the islands. Later, other Marine units would reinforce the battalion, including a group of heavy machine-guns (some 29 men, with 0.5 caliber machinegun), the First Platoon of Marine Amphibious Engineers (20 men), and B Battery of the Marine Field Artillery Battalion with six 105mm guns. Originally, the machine-gun group belonged to a Marine Machine-gun Company hastily assembled in Puerto Belgrano, the principal Argentine naval base. This company, some 136 strong, had a total of 27 guns and was divided into three platoons. When the company arrived in the islands, its platoons were dispersed, and the Marine Battalion used only one. The rifle companies were M Company (203 men), N Company (200 men), and the O Company (100 strong).
As to what to defend most strongly, the Argentine General High Command in the Malvinas decided to defend three “key” zones: Puerto Argentino (Port Stanley), the capital of the islands; Darwin-Goose Green on Soledad Island (East Falkland); and, for political reasons, Fox Bay and Port Howard on Gran Malvina Island (West Falkland). Map 2 shows the location of the Argentine key defense zones in the Malvinas Islands. All the Army units rushed to the islands without their heavy and support equipment. For instance, they lacked sufficient field kitchens, winter clothing, communication equipment, or even spare batteries to properly support the troops.
Unlike their Army brothers, the Argentine Marines were well fed, and they had good clothing and improved communications equipment. Also unlike the Army conscript soldiers, the Marines had undergone night combat training, and, principally because the battalion had been based in Tierra del Fuego in the far south of Patagonia, its members were adapted to the rigorous climatic conditions. During the period between their arrival and the fighting, the Marines were kept busy preparing their positions, digging bunkers, cleaning their equipment, and reconnoitering the terrain and coordinating and organizing fire support. The battalion was also well provided with entrenching tools. Because of their experience in Tierra del Fuego, they were well aware of the hardness of the soil of the islands surrounding Argentina. Therefore, the battalion flew to the islands provided with iron bars, which were very useful for digging in the rocks.
The actual combat between Argentine and British forces begun on May 1st with the bombardment of the airport by a Vulcan bomber of the RAF. The British then harassed the Argentine garrison, using continuous naval and aerial bombardment, as well as small-scale commando raids. Every night after May 1st, two or three British vessels bombarded the south coast of Puerto Argentino from 12 to 15 kilometers out at sea. after the British landings in San Carlos, the General High Command in the islands rearranged the defensive perimeter. Initially the commanders had expected the most probable direction of attack to be from the sea, with the British landing troops in Puerto Argentino or its surroundings. But later, those in charge decided to defend Puerto Argentino also from an attack from the west, while maintaining strong coastal defenses to the east and south of the capital.
Between May 29th and June 3rd, the High Command established the western side of the defensive perimeter along the mounts that surrounded Puerto Argentino. These ran from
north to south, and they comprised Wireless Ridge, Longdon, Dos Hermanas (Two Sisters), Harriet, Tumbledown, William, and Sapper Hill. This new perimeter was 48 kilometers long, and the Argentine forces could guard only 37 per cent of it. This meant that there was enough space left uncovered that the enemy could take advantage of the gaps and infiltrate the Argentine positions. Map 3 shows Puerto Argentino, its surrounding heights and the Marine positions around Mount Tumbledown.
After the fall of Goose Green, the British troops moved some chroniclers - say “yomped” - west toward Puerto Argentino, and after May 31st British land and naval artillery began pounding the Argentine positions in the mountains. Until June 8th, the only land actions were intense skirmishes between patrols. For three days the British probed the Argentine defenses and prepared for the final assault. Then the battle for Puerto Argentino began on the night of June 11th. The British plan encompassed two phases, the first phase being the conquest of the first line of mounts. The entire 3rd Commando Brigade under Brigadier Thompson would take part in this attack. The Third Parachute Battalion would attack Mount Longdon, the 45th Commando Battalion would confront Mount Dos Hermanas, and the 42 Commando Battalion would move against Goat Ridge and Mount Harriet. During the operation, the frigates HMS Avenger, HMS Glamoran and HMS Yarmouth would provide the supporting naval bombardment.
At about 11:00 p.m., local time, the British attacked simultaneously all along the western front. The attackers outnumbered the Argentine defenders by two to one. The British were using all of their available forces in the attack on Puerto Argentino; there were no more fresh troops in reserve and no more under way from Great Britain. Also, as Middlebrook notes, the British troops were tiring and were suffering, as were the Argentines, from the increasingly cold weather. The Argentine positions facing the British commandos comprised part of the 7th IR in Mount Longdon and part of the 4th IR in the area of Dos Hermanas, Goat Ridge, and Harriet. By the early morning of June 12th, after very hard fighting in some areas, British troops occupied the outer ring of hills surrounding the Puerto Argentino defenses. After losing these positions, the Argentines adjusted their defensive perimeter during the 12th of June. A Company of the 3rd IR advanced and occupied positions northeast of Mount Tumbledown, working with B Company of the 6th IR. At the same time, O Company of the 5th Marine Battalion occupied the heights near Pony Pass, southeast of Mount Harriet.