I suppose he did what he had been ordered to do, to achieve what he had been ordered to achieve, with the resources that were available. With what was available, and in the timescales imposed, I really don't think anybody could have done better. If Argentina had waited until they were really ready, we would now be talking about the Malvinas, since there wouldn't have been enough RN to go there on anything other than a courtesy visit. Our government at the time was ready to convert the RN into a UK coastal patrol force.
Like Circlip said, hindsight is a wonderful thing. Its just a pity for all the lives that were lost on both sides that none of the politicians from either side had foresight. Thankfully, he was nothing like as pugnacious as Beatty (who would have lost many more ships), nor as cautious as Jellicoe (who would have avoided contact, probably), and there is very little chance of another Nelson (who would probably have left us with Argentina as a Crown Colony).