Sink rate was a problem - the Mk VII (1939) terminal velocty was 9.9 f/s and the Mk VII heavy (end 40+) tv 16.8 f/s.
Note though that initial fuze settings were only 300 ft, later 600 ft and finally 900 ft or 1000 ft.
The US Mk 6 (standard in early war) tv 8 f/s (later 12 f/s), and the later Mk 9 (standard in late war) 14.5 f/s - some later 22.7 f/s.
Again though, fuze setting were originally only 300 ft, later 600 ft and even 1000 ft.
IIRC, SHIII has only one type of DC

and the modders have had to work wonders to get round this problem!
(Data from Campbell)