Hey again,
I wouldn’t have said the UK’s ASW technology was poor in 1940. They had sonar/asdic as well as basic radar. The key thing is that there simply wasn’t enough escort ships to guard all the convoy routes, and air power wasn’t available in the mid-Atlantic. The RN pretty much refused to let many of its destroyers be used as convoy escorts as they feared depleting the Home Fleet.
Again, I feel the best way to represent this in AAE40 is to compel the RN to remain in UK waters through threat of invasion etc, and then encourage the Germans to whittle away UK income through convoy attacks. This will force the UK to invest in destroyers and other replacement units, rather than stacking up large and threatening France/Germany with invasion as early as 1940-41.
The UK can still have a powerful fleet but it will be a bit of a paper tiger if it’s only got 10-20 IPCs to spend every turn due to convoy losses.
Cheers,
Lozza007