Applying this redirection effect doesn’t change whether the damage is combat damage.

If noncombat damage would be dealt to a planeswalker you control, the planeswalker redirection effect and Palisade Giant’s redirection effect apply in whichever order you choose. No matter which order you choose to apply them in, that damage will be dealt to Palisade Giant instead.

If you control more than one Palisade Giant, you choose which redirection effect to apply. You can’t divide damage dealt by one source. For example, if an attacking creature would deal 8 damage to you and you control two Palisade Giants, you may have that damage dealt to either of the Palisade Giants. You can’t have 4 damage dealt to each Giant or choose to have the 8 damage dealt to you.