The Misguided Master is possibly the best Master to be training under if a qualified instructor cannot be found. That they were misguided at all does show some mental weekness. However, that is not anything to base their skill on. Since most misguided people misguide themselves, there is no cultural system to work against. Like any instructor, the only qualification should be whether or not they have a skill which you want.
The Misguided Master also has the potential to learn from his students. If a student surpasses the master, the master will usually assume that the student is especially gifted. The Misguided Master does not have a problem with people who have a higher level of skill. It simply shows the awesome scope of their teaching ability. Also, since all misguided people are blinded by their own loyalty, they are the most likely to notice a lack of skill whithin themselves. They can notice this flaw and correct it without having to damage their ego or their image of their own Master. Many skilled Masters have a memory of their own misguided attempts at something and how that realization set them upon their current path. The Misguided Master is also the only one which tells the truth about their own efforts. As such, they can be helped over time.
There is not much more to be said about this except that the Evil Master and the Incompetent Master will pretend to be misguided if they are ever found out.