We have had between 4 ( I did them myself, spent more on ibuprofen for the back pain after ) and 16, and after the first lot ( back pain was bad - to be fair I have been a nurse for many many more years than I want to admit, so back pain is a given ) and 16, and each year since got them done by a professional. Advertised on a facebook group, as well as other small holder groups, we accepted paying a set amount (£50) for anything under 25 sheep, then a per-sheep rate after ( we don't, and will not have that many) So now we contact the person, and for £50 we get any amount under 25 sheep shorn, and he brings a generator, and I get the sheep into a small pen accessible by his truck and trailer, and he does them all. I fit in with with whatever date he and time he wants, and it is a lot easier. No wounds, no stress, takes about an hour, and he is kind and careful with them. I send the wool to a friend of a friend of a friends Mum, who spins it , and sends me a few balls of wool, and I made a scarf. It was ugly. I shall stick to other things.
Worth looking online for small company people who will do small numbers, and negotiate a good price for fitting in with their timescale.