@Yannis: most of the organizations seem to exist because of the teacher who started them. I get it. In my own dojo, one guy learned forms and partner practice that keeps people so far apart that they are guaranteed to miss when they swing a Jo at someone's head, so people tend to move quickly with power. I was taught slow practice, but stopping the Jo an inch away from someone's throat. A white belt student who keeps my teacher's ma-ai but the other teacher's speed and power is unsafe. Interesting and fun variations from other schools now would confuse me as a beginner.

Does Yoshinkan require someone to restart? Sometimes, and there is a good discussion on how organizations may make allowances for experience in the thread "testing before minimums." Ultimately, Yoshinkan dojos do teach different starting stuff even if it does all become Aikido later. I have no problem wearing whatever color of belt if there is information to learn. I wore a white belt when I found myself in a Tohei lineage dojo. We all have a choice to rise above politics with so many of the original principle players dead and dying.

I believe previous posts had you mentioning Steven Seagal. I don't know much about his organization, or if he acknowledges the black belts of every style of Aikido. Maybe you know more?

Beyond personal integrity, I think the truth of any system is there is strength in numbers. Without support and students and growth, any excellent practitioner's work is lost when they are injured or dead.