You must not have watched the full video. But Askren doesn't like mount or back mount because in it games the BJJ system of securing position so an opponent will go back and forth between those two spot to avoid a postition stabilization and thus avoids the strikes.
However in crucifix and back side control there real isn't anywhere to go. All positions become bad in that scenario. This is exactly how an Askren or Khabib fight plays out. The rain down punches from a pinning position (side control or crucifix) or riding position back side control (often with a base broken down)
Regarding Sambo...because they use grappling in the context of striking unlike BJJ. they prefer positions similar to the wrestling one.