MLS Experiment

Hi need your guys help... So i follow SteelSwords on yourtube and he does a great MLS franchise with Vancouver Whitecaps like what i wanna do is kind of use his idea where I improve Canada World Ranking and such but like only bring in players from my Youth academy intake however my question is if i set myself to only 10 internationals how would i come up with a rule for that. like should i only sign like 16-17 yr old youth intake international players let them develop and then only have those 10 18-19 yr old international players when they become 18-19 international players bring them up to my MLS squad like just not sure how i want to put the international idea into this whole thing. I thought maybe someone on here could bring up a good idea..

thanks for any help or suggestions greatly appreciated.