Not all Majin Princes were equal.
Just like how all powerful Ranked Monsters were divided into Alpha, Overlord, and Sovereign, the Majin Princes and Kings also had different subrankings.
Initial, Middle, and Peak.
Camazotz was a Middle-Ranked Majin Prince, while Arundel the Destroyer was an Initial-Ranked Majin Prince.
Kamrusepa was a Peak-Ranked Majin Princess who was just a step away from becoming a Majin Queen.
Even Majin Princes and Princesses of the same Rank didn't have equal strength. Some were stronger than others, just like how Zion was stronger than all the Rookies in the world.
Although the Five-Headed Serpent was only at the Initial Stages of the Majin Prince, it was already enough to give Camazotz a headache.
His strength lay not in his attack power, but in his speed.