Unsure about rabbits eating habits

I have a 13(?) week old male rabbit (thumper) and a 10 nearly 11 week old female (lily), they are kept separate until me or my girlfriend can supervise (we aim to get the boy neutered at 16 weeks but for now they are out together and just explore).

House isn't great tbh and just waiting to get a decent puppy pen so I can at least know they aren't potentially chewing any cables.

Anyhow, thumper goes mental for pellets but scratches at his hay, so it ends up on the floor of the cage. Lily doesn't eat many pellets and they're left in her dish, she eats hay relatively fine.

He and lily both have spinach as I was told by the vet nurse when enquiring about prices that spinach is a "meaty" green whereas lettuce is more watery.

Now, is there anyway I could kind of force him to eat more hay because I feel like I'm feeding him wrong and it's stressing me out, especially when I want them to have a decent living space that I'm trying to set up.

Is there a trick to how their food should be worked out or is it a case of just eyeballing it and hoping for the best.