You need to learn what your system has first..
Then make a list of what you think is " automated crud".
You need to keep devices which are in your system to protect the compressor ( the low pressure cutoff switch and the high temp cutout switch ) and you need to know what of the auto crud operated several systems at the same time... like the fresh air vent, temp control, freezing control, etc....
You can make a simple system but you don't want it ' more simple' than possible.... and you need to do some load research.... a meltdown is not allways as small and neat as what is shown in the picture.... could happen in a tight space, be worse, and start a fire...
I suggest you first get a paper copy of the Mercedes Heating and Climate Control manual... this is a book by itself... not part of another factory shop manual. Then you need a generic Auto Air conditioning manual... to know what you have and what is ' extra' and what is for safety.