No worries, its a SUPER common mistake that subs can attack subs at range, but submerged shot on all units states "...local enemy submarines..." and the glossary of the rules states:'local: in the same sector as another unit"
Sounds good, all of those ships have 4aa so I will just throw all of them at once starting against Sunderland 1 and of course if they abort it, the other attacks will be against sunderalnd 2: Pegaso against Sunderland 1: q73p1MmJ4d6 Nere 2 against Sunderland 1/2: 4d6 Nere 3 against sunderland 1/2: 4d64d6·4d6·4d6