Anakin honestly couldn't make up his mind on his class. He was a Sentinel to begin with, except he thought he was too cool to use a second lightsaber and since he was only fighting trash mobs up until the chapter 2 boss, he was able to get through unscathed. Then when he got to his chapter 2 Boss, aka Dooku, he rushed in and was whooped by force lightning. Obi-Wan fought Dooku while Anakin was respawning, but he didn't have enough offense in his tank spec to deal with Dooku. Luckily for him, Anakin got back just in time before Dooku could get in the killing blow on Obi-Wan. While Obi-Wan was incapacitated, Anakin finally started using his second lightsaber, but it was quickly disabled. Only now able to use half of his abilities, he lost. After that, he decided to re-roll as a Guardian, but since he saw Obi-Wan had trouble, he specced vigilance instead. Eventually getting bored with the Republic side, he rerolled as a Sith, going with Juggernaut and speccing Vengeance.
Yes, I'm obviously joking.
TL;DR I have too much time on my hands