A-ha! I'm watching this retrospective from someone playing the Wii version of Prime 2 and they also complained about having absurd difficulty hitting the weak point of the Grapple Guardian! It's not just me! Vindication! ๐
youtu.be/QeQNsF5eJUU
They also call out the busted lock on, which was another constant annoyance. The game just loves breaking your lock on from the enemy for what feels like no reason, but doesn't completely disable the lock on. You can't look around again until you realize it broke and release the button.