That's right. There is no comparison between Sith Lord / Jedi Master. Both are Force users. The only 2 differences is
1. Jedi Master got Inspire Followers, but Sith Lord got Dark Side Corruption, but DSC won't work if Sith Lord is in Light Side path.
2. Jedi Master's light side mastery is +5 Wisdom, which means more chance to succeed a Force Power attack and more FP. But Dark side mastery is simply +50 FP, but it doesn't increase the Wisdom.
Again, there is no comparison between Assassin or Watchman. Both is stealthy PC and got Sneak Attack and truck loads of skills. For details, I don't know much.
According to the diagram, I think Jedi Master will defeat Sith Lord for sure, if pure Force Power, LS and DS respectively, same stats [Not including bonuses], same equipments, and same Force Powers. Jedi Master got higher Wisdom, therefore more likely to succeed the Force Using.
Jedi Weapon Master also can defeat Sith Marauder, IMO. Weapon Master got constant upgrades for strength and increasing damages, so he doesn't need a temporary damage boost, especially with LS Mastery. Even with full upgrades, Sith Marauder never got enough strength, and without at least 3 permanent damage increasing bonuses...
Jedi Watchman and Sith Assassin...I don't know.