What's the trick? I attacked a convoy in Spr 43 with a IXC/40. Escort was ridculously easy to penetrate-way too close to the convoy. No air cover at all.
I guess random generated escorts are only a Km or so from the convoy. They need to be 5+Km distant to be effective escorts.
Anyway, I sneaked in during broad daylight right inside the columns fired 6 torps hit with 4 sunk 2 ships.
Way too easy for 1943...