Minimum 3 coaches per age group, this allow training sessions to flow and for it to be a more enjoyable experience for each one of the players. You can never grow short of coaches. The better quality the training sessions the more chance you have of player retention.
I don’t know what access you have, but have a chat with your local educational school. A common thing that happens here is on a short term basis a lot of physiotherapists are sourced from universities or colleges in Scotland, it allows the students to enjoy some real life experiences using their knowledge and gives the club some professional protection against potential injuries.
Apply the same idea and principle to other potential roles within your club, good examples would be sports analysts, personal trainers, coaches, medical related subjects and so on.
This sort of text again is purely through experience and ideas that have either been presented by me or perhaps ideas that have shown up through conversation. Take the information and again don’t take it literally, consider the idea potentially reshape, reconstruct, reorganise or simply use it at is. What matters is wether it is useful to you.