There is no bad choice.
I am leaving a small club and we were prepared for any team to get inside of the club and battle the way up. This was the strategy given to me by a former pro who trains here now locally.
If he goes to MSI, it appears from other posters he will have better talent to go up against weekly in practice and get the best coaching MSI has available. He will have to supplement outside of team activities with small-sided play and training to match what the kids are doing on the major clubs.
If you are in Moco, some options are Next Star, Ballerz and Limitless.
If he gets into a system, Bethesda for example, he will have opportunities within the system to train with the top talent outside of standard practices days. In my experience, the clubs notice when you are putting in extra work, even if it is outside of the organization, and they will promote because they can actually see you progressing.
We were with a small club and did a supplemental training at Bethesda and my child was getting his lunch taken from him at one of the Bethesda trainings. His personality is to fight and he wanted that type of challenge and he grew into the player he is now.
You can accomplish what you want at both but you will have to do it different ways.