I have been reading quite a lot on 1796 in Italy recently as part of looking at Napoleon's intelligence efforts in the Italian campaigns. One theme that keeps coming up is the "stupid Austrians" dividing their troops in the four main efforts to relieve Mantua. I noticed Zack has perpetuated this myth: "This type of plan was typical of Alvinczy, who had not seemed to realise that if he united all of his troops against Napoleon he would have a great numerical advantage – more than enough to defeat him. "
There is actually a good reason why the Austrians divided their troops - the Alpine roads were so bad that they could not take any more troops, so that if all had been on one route, it would have simply meant that Napoleon had to met the head of the column before the rear units could intervene. The other side of the coin then becomes that Napoleon had to know which was the main force. That is where the intelligence effort came in!