She didn't dominate him, and that's with a large environmental edge to boot 👆
Not to mention, Shaak Ti beating Galen Marek, regardless of his incarnation and even under fair circumstances, would still pale in comparison to Malgus's dueling accomplishments. Beating Kao Cen Darach and being accoladed as one of the best warriors in the Empire 28 years prior to Deceived, tooling Satele Shan twice, defeating Ven Zallow who casually speedblitzed numerous Sith and was regarded as a more famous kill than Darach (who if you remember was stalemating an early Malgus and Vindican simultaneously), ect, are all better claims to skill than Shaak Ti struggling with single MagnaGuards, having a hard time with a weakened Galen Marek with environmental edges, getting wrecked by Grievous twice ect.
Malgus is better than Ti in pretty much every category, physically and in terms of power.
Malgus easily
As for Aryn Leener: http://www.comicvine.com/profile/s_w_legend/blog/aryn-leener-respect-thread/102062/
Shaak Ti have nothing on both.