I know high fatigue levels increases losses and lowers CV rolls. And yes no air support and no art support. Also high morale division seem to have lower losses than high morale divisions. (Especially notice that with panzer divisions). And yes hasty attack will increase losses when compared to deliberate attacks.
But attacking a brigade size unit thats in the clear and isnt in a fortified position seems high for losses.
I imagine its just the RNG factor.
