I have a feeling he is real omni king

jiren > vermuth

https://www.youtube.com/watch?v=58jQO9be23U

thats my theory on it,
I think he is manipulating zen-oh because of his childish attributes, and in the end it will end up being like goku/hit/jiren/vegeta/frieza all teaming up to take out the grand priest.

I personally think that is why whis agreed to train goku and vegeta. because he never actually stated why to beerus, he just laughed when beerus asked and said "i dont have to tell you everything"
I think whis knows his dads a bad guy and he took goku and vegeta in because he saw potential in them to stop him.

I could also be completely wrong. But i hope thats what ends up happening.

this all boils down to the tournament getting interrupted before it finishes.
etcetc.

I would agree except for fact that whis and othets are angels. God created angels which in my eyes makes grand priest omni king. How the hell could those 2 zenos be around for billions of years and be that dumb.

I agree with both.
Another theory proposed is that Zen-Oh is not actually the highest power given his extremely childish nature

in the manga zeno is not that stupid i think

Just realized Master Roshi is the Harvey Weinstein of anime. Think of all the young girls he has sexually harassed and assaulted. He was even going to molest Launch in her sleep.