Engine and gearbox make a massive difference to driving in low grip conditions IMO. In a 2l petrol manual you have good control of the power and hence the car. The problem comes with diesel automatics where all the power comes low down and you don't have a manual clutch to control the transmission to the wheels.
I remember driving a 530d auto in the snow and you had to have your wits about you when pulling away.
Mind you that was a good few years and I'm no auto expert. I understand modern auto boxes are considerably smarter than me now!