“Some of my Under 11s want to swap positions just as I had found them the perfect places to play. Should I agree?”
In a word, yes! It’s a tricky one, but the long and short is that we’re all in youth coaching because it gives kids enjoyment, plus a sense of contributing towards a goal and each other.
In one respect, you could say you’re preventing that by forcing players to play in positions that they don’t want to be in, and it’s clear they wouldn’t be asking to swap positions if they were truly happy playing where they are.
It’s great that you’re thinking about individual player development, and there’s no reason you need to stop that altogether. You can still give players preferred positions, even if it means they’re only in those roles for maybe 70% of the time.
A winger who believes he wants to move into a role in the middle of the park may well change their mind after a bit of time there. In addition, you can always make small gestures to satisfy someone’s desire to play somewhere else.
For instance, if you have a defender who wants to go up front, send them up for corners, or see if they can despatch a clinical penalty. Lean to their wants and needs ever so slightly and they’ll respond to yours.