I choose for my son to play against 2025's. That's why there is a "2025" classification, right ?
If I want him to play against older kids I would have him play up, which is what he sometimes does for his PAL team. That's my choice.

Most "holdbacks" (those who play down specifically for sports) have one thing in common: they are just NOT good enough to play with kids their own age! They know it, and so does everyone else.

It's all good tho, Karma!