Simple Snorlax Question Again.... Sorry

Do you need an attacker or defender?

Lick/Body Slam is the best attacking moveset.
Zen Headbutt / Hyper Beam is the best defending moveset.

I vote for the latter since I view Snorlax as a top tier defender. He's a viable attacker but goes through too many potions and won't benefit from type advantages - so if you have Vaporean/Exeggutor/Dragonite/etc... then you're probably not attacking with him. You also care a lot more about high CP when defending (discourage attackers and place higher in the gym) whereas attacking doesn't matter as much. For training you even want lower CP!

walking with 1 snorlax or an other snorlax , is same , no?
just earn candy^^

I would probably prioritize the defender (Zen Headbutt). Even though Snorlax is a good attacker, it still is a better defender. For me I don't use much else for attack aside from Dragonite. Snorlax has kinda low DPS and it takes a long time to kill something compared to Dragonite, also the potion usage is a lot higher on Snorlax. Zen Headbutt/Hyper Beam is also a great attacking moveset (Lick is a horrible defending move) so it's definitely more flexible too.

Power up the ZEN/beam one. Walk with the lick/slam one