u/Cubeiq

I am confused because I keep getting different answers.

I have a deck with a lot of Arcbound Creatures. They all are 0/0 creatures but have Modular X. Where Modular sais the creature enters the Battlefield with X +1/+1 Counters.

Why can I copy an arcbound creature with The Jolly Balloon Man but I cant with Helm of the Host.