Both will come back from down low. Common "Apple blossom" is actually 'Donard Seedling'. Real 'Apple blossom' like Pink Princess = 'Frades' but pink-and-white instead of all pink. Have only seen that at local arboretum, where it froze down and is probably no longer present.

Be careful pruning Nandinas too low because they do not sprout back from side shoots. They are sort of like palm trees in the way they grow.

Nandina is a caning shrub - cutting back old, leggy growth at ground level will encourage new shoots from the base.