I read an interesting article about the Lanc a while ago. The Lanc would have been about 50 mph faster without any turrets and their associated weight, ammo, drag etc. Plus it would have had two less crew. Someone far cleverer than me (that's everyone then) applied their statistical minds to it and worked out that far less Lancs and crew would have been lost had it been produced sans turrets.
Regarding the Mossie performance it also had a high Vmca at operational take off weights which sadly caught a few crew out, and I believe the Beaufort was an absolute dog of an aircraft all round.