I think I originally posted that "note" as a footnote to the original Landlubber's guide when it was copied to CADC. I removed it a few years after... I forget if it was because DW had progressed beyond the point that it was relevant or because I thought it wasn't really appropriate to be adding unsolicited opinions. Either way, it seems remarks made on the internet have a certain permanence to them...
It looks like most of the information around page 35 is taken from my ASW/ASUW weapons employment posts from
CADC's submarine forum. Those are old posts from Stock DW 1.01 or so, and some of the information is out of date. Two things I noticed are that the decoy %ages are from before the player could adjust that in the .ini, and the torpedo ranges are from before torpedo range varied with speed. I've made some edits to those posts over the years and added some updates here and there, but those do not appear in Landlubbers 0.6.