In the case of Moni:
Yes he teaches Jujitsu and Judo as he was a student of those arts.
He had a school dedicated to teaching those arts and it was not well known and neither was he for the most part until he remembered all his Krav Maga Training and his membership in the Elite Israeli SF.
The problem occurs when Moni makes claims to support his assertion to teach COMBAT KRAV MAGA or Survival Krav Maga as he supposedly learned,altered,(when working with Imi), and taught,so he claims ,to Elite SF units of the Israeli Military.
As we now know none of these claims are/were true.
Anyone with and without a Black Belt can train people in Self Defense.
They would be made or broken by their materials and the Majority,without these special claims,would have nothing and be unknown.
(as Moni was unknown until the creation of a fake bio and creation of Survival KM)
The Fake or False claims made these people rich and known.
If it were just skilled based and not hyped based then these Fakes,Frauds and Pretenders would be No Ones With Nothing but a little school,MAYBE.