True. Thatcher may have been many things but she was no fool. The only reason she might have ordered Woodward as the Task Force Commander to make a direct assault landing over the Port Stanley beaches (a plan that IOTL was considered as an option and dismissed because it was too high risk) would be if the international sitution was such that a quick attack was essential to retake the islands before a UN Ceasefire was imposed. The risk would have then been that Argentina would be left in de facto pssession and it might have proven impossible to ge them out by negotiation.
These are the only circumstances where such a high risk military option might have been attempted. As previously discussed the military objectives would likely have been achieved. However, Argenina would have been able o claim a moral victory having been perieved to have put up a good fight and yhe Junta would have been in a reasonable position to retain power at least for a while despite losing the war.
That assumes OTL force levels and therefore OTL risk levels.
Personally I think prerequisites are a proper fleet carrier such as Eagle or Ark Royal, a 6" cruiser like Blake or Tiger and the Hermes operating in the Commando role. These bring an array of capabilities that were not present IOTL and thus create an entirely different risk profile. For example a Buccaneer squadron could be tasked over a period of several days to destroy artillery batteries or Battalion HQs or some other vital target set. The 6" cruiser could also be given a particular tasking that would make an opposed landing easier. The Hermes could land a company or two deep into the rear, perhaps at a junction of two units while the main assault was conducted.
These capabilities would alter the decision making process for all concerned.