I was confused by the rules for a while regarding that. I thought it was each group (all units that hit a 1, all units that hit at 2) roll for all the units.
When I moved on to Global 1940 and brought that mistake with me, it led to a problem where 12 US bombers (give or take) were unable to sink a Japanese fleet of 1 aircraft carrier, 1 destroyer, 2 fighters, and 1 battleship.
I figured it out later on, and I’ve been playing correctly for a year.
