Well walking sticks eat bramble only so they wont eat the chams.
The leaf chams will need at least 1.5 square foot of grounds space more if possible. They tend to stay at the bottom in the leafs during the day try to find food and water and then they climb a little way off the ground to sleep usually no more than a foot off the ground.
They eat tiny bugs so the baby walking stick would mostlikly become pray.
oh just to let you know if you have on eof the smaller of pygmy species (3 inches or least max length) then they both can live in a ten gallon or 20 gallon long.