I think he's too young to expect him not to poop/pee during the night. Thats kinda like asking a baby not to wet its diaper
I use to keep Meka in a playpen w/ blanket on one side (cuz she kept wetting her bed) & pad on the other. After a moment, they'll get it. Its important to enforce good & bad behavior now. Praise him when he does go on the pad and correct him when he doesnt. Proper crate training, should be with a crate that only allows them enough room to stand up and turn around. If there's room for a pad etc... then its way too big. Crate training is designed to limit their space, so they will not want to soil in it because there isnt enough room, basically. I only started crated training at 10 mo's with Meka, so Im not the expert nor can I say what the best age for it... but I hope this helped a lil