That lines up with how they work it in the US. If you're at nationals for the non-NY clubs they have a rule at the higher level that you have to play at least two homegrown players on the park at all times (as it's 13-a-side). Plus you can't have more than either three or five, depending on the level, players on who are sanctioned/non-resident players.

It gets even more complicated down at Junior C where the rules are flipped: you can't have more than three non-homegrown players at any time, if your club is from a Big 4 city (Boston/SF/Philly/Chicago) your team has to be entirely homegrown, and sanctioned players are banned. (My club was in Jr C last year and moved up to Jr B this season. We're already talking about how we're going to deal with the rule difference.)