I'm a bit confused; assuming you are aiming at the US situation with this, I kinda fail to see a clear contrast between entrenched oligarchy and ochlocracy.

Isn't the Trump side a pretty good example of combining both?

Riling up the masses, promoting selfish "got mine" attitude from the top down, partial and weaponized use of the law are basically textbook fits for mob rule?

On the other hand, if you put Harrison or Waltz on a "entrenched oligarch" scale, there is no way they weight as heavy as Trump and his cronies in the current administration, at least in my view? Both of them did an actual job instead of just enjoying a life in the spotlight funded by generational wealth and the work of others...

I'm very interested in conflicting viewpoints-- if you disagree with my perspective, please tell me how instead of just downvoting!