Forward throwers was the huge allied advantage. That and code breaking. The latter is so critical to really understanding the success of allied ASW and failure of axis submarine warfare. Minus the sigint and code breaking, we'd have taken far worse losses, even if our kill rate was similar on subs. The attrition war required that u-boat losses be sustainable with disproportionate damage to allied shipping. 1-2 sinkings per u-boat lost would not cut it.
We are critically hobbled WRT realistic IJN ASW by the fact that DCs in SH are aimed at specific depths, and we have NO control over realistic depth settings. There should ideally be a control for DCs that sets the allowed depth increment at the very least (for the IJN it would then be to the nearest 30m).
In actually fact, IJN ASW assets dropped in patterns of depth and spread.
