You seem to have misread my posts.
I said the only real GAR character to have lost is Dio. Kamina hasn't lost. If Kamina loses then another GAR character will have been lost. There are other real GAR characters who have lost but I can't be bother trying to recall them. Take these threads with a pinch of salt.
I also didn't say Hosaka isn't GAR, he just doesn't come near Dio's level.