Technically it says you need those processes which are required to ensure quality. (I say product / service quality and system's quality)
I believe it depends on the size of your company and the nature of its business. Huge chocolate factory will have R&D, production, distribution, customer care, HR, H&S (in case of integrated systems). They need it because of food hygiene, shifts, etc etc, it is easier to control business via processes. Its not that much what you are going to prove to auditors, it is about logical and smoothly working system, so processes can be very useful, sometimes it is good to have more than 1. One man band mobile hairdresser would have service delivery process and within this process there would be things that she/he does and they just fit into simple procedures like purchasing consumables, pricing system, days for self development, service itself, it all makes up the process of her/his business.
I'd look at 4.4.1. and draw a process chart and go from there. I told my auditor that I had 11 perfectly functioning processes but as we grew, there is a new one, number 12 (Training). My company, I know the specifics of the job the best. Auditor agreed.