Batteries for winching

Hi all

I am in the process of rigging up a couple of 105ah deep cycle batteries in our trusty 75 series LC to power 2 Engles and some lights. One is a 29l that we use as a freezer (old but still works well) and a 39l to use as a fridge. Cranking the oiler to life is taken care of by a couple of N70ZZ,s in parallel. Isolation of cranking and camping batteries will be done with a simple manual rotary switch. Yes I realize that there are automatic electronic isolators available but I am quite happy to lift the bonnet, have a quick check around the engine bay and turn a switch.Also previously any winching was done with a Tirfor. Handy bit of kit but getting to be hard work as the years roll by. I have come to the horrible realization that this isn't going to get any better so I am in the midst of fitting a 10000lb electric winch.
Question (after all that rambling) if I am in a situation requiring winching would it be better in the context of good battery longevity to use either cranking or deep cycle batteries, or use them all? I am not sure if using batteries intended for different purposes together may cause harm.

Thanks for any input in advance

Cheers Pop