Popol is the leader and must always be under Kupa's full command (hence the guide refers more to Popol) and follow his position.
Gameplay Popol and Kupa manage two different heroes at the same time. Popol is a backline similar to mage/marksman in terms of safe positioning, while Kupa is the initiator.
Popol can disrupt the opponent's lane with his distance advantage, he can deal damage from a safe distance without taking any damage, but it's very important to keep Kupa safe and not let him die easily, call back Kupa when he takes more damage.
▶️ 3Speak