i think that probably the manual was written that way to maintain some of the "randomness" of the campaign. and to give the player an element of "if you want the information bad enough... you'll find it"
It was written like a history book so as to prevent players from going and sitting in one specific spot for weeks just to sink an entire task force that they knew beforehand would eventually show up on a pre-destined date and time and place.
as opposed to writing the
exact date, time and location of every scripted task force and battleship for the entire war. - whats the fun in that???
If i know every single move my opponent will make, when he is going to make it, how he is going to make it etc... there is no element of suprise, no element of danger, no challenge whatsoever.
thats chicken **** if you ask me