If you can find a copy of the March, 1984 "Proceedings of the US Naval Institute" there was an article titled "Where Were Those Argentine Subs?" Iirc, it had an interview with the captain of ARA San Luis.
I do know that San Luis made a torpedo attack against British ships at 1005 on May 1, 1982. This was ~20nm north of Port Stanley. The frigates HMS Brilliant (Type 22/1) & HMS Yarmouth (Rothesay-class), along with 3 Sea King helicopters from HMS Hermes prosecuted the contact for ~20 hours and expended a lot of ordinance, but San Luis got away.
HMS Conqueror, as we all know, was patrolling south of the Burdwood Bank (an area of shallows ~200nm south of the islands). She located TF79.3 (ARA General Belgrano, ARA Hippolito Bouchard and ARA Piedra Buena (both Allen M. Sumner FRAM II destroyers refitted with 4 Exocets each)) on the afternoon of the 1st between Islas de los Estados and the Burdwood Bank. The SAG was on course 110 at the time. Conqueror shadowed the group for a day before attacking at 1857Z on May 2nd.
I have a sketchy report that HMS Spartan detected "a group of destroyers and frigates" further to the north. This may have been TF79.2 consisting of ARA Hercules (Type 42 DDG), ARA Commodoro Py (un-FRAMed Allen M. Sumner-class DD), ARA Segui (Gearing-class DD) and an oiler All three destroyers were refitted with 4 MM38 Exocets.
I say this because the carrier ARA Veinticinco de Mayo (which was escorted by ARA Santissima Trinidad (Type 42 Destroyer,also refitted with 4 Exocets), forming TF79.1) was not detected.
There was another group, TF79.4 which consisted of the three A69 Missile corvettes (4 Exocets each) Granville, Drummond & Guerrico accompanied by an oiler.
The sketch I have for the afternoon of May 1st shows TF79.2 (and, hypothetically, HMS Spartan) 80-100nm east of Puerto Deseado, and TF79.1 & TF79.4 ~80 miles further to the east.
I have no information on the whereabouts of HMS Splendid.
Hope this helps.
Just because it's stupid, futile and doomed to failure, that doesn't mean some officer won't try it.
-- R. Rather