I'm quite certain that the city where Lula coaches has way less than a population of 100k
Personally: I find it really strange to charge kids for training but that's a cultural thing. Our entire system (applies to all sports) is based on adults providing their services pretty much free of charge for the greater good. It's not impossible to recruit good coaches since they received the same type of service in their childhood. Karma. They may get some kind of symbolic pay from the club but it's really small. Some clubs will have full time coaches but this is not the norm.
I think the clubs need to charge the players to be able to survive and to be able to keep coaches. I like how you think But i Do not think alot of people would Do it completely for free. I would almost Do it for free since it is really fun when people listen, fight hard and try to develop But it is also very hard mentally to be a coach i think, like other teaching professions. I feel that it is sometimes hard since i almost want more than the players and they Do not listen or fight well. If is is like that our a long time it is difficult as a coach to keep up the good work or even continuing being a coach. It would ve fun to try to coach kids in a club where they want a little a more. It is really fun to help people that wants to learn. I feel that is is the most fun to help adults, they appreciate the help more since they Do not get so much help and are not used to the attention.