drop bear
Sr. Grandmaster
You are once again being obtuse. Self defense training addresses what people will commonly attack you with. It won't be common for multiple people to each have a knife and attack you.
I will not question whether you have or not used MMA to deal with a knife, but I will ask you what does MMA normally do about knife? What training does MMA offer for knife defense?
How often have you been attacked by a knife to consider it common?