why do you think LMAX disruptor runs inside many big exchanges? have you read some blogs online? LMAX disruptor does not run at "many big exchanges".

Disruptor is written in Java. LMAX itself is a tiny exchange that largely deals with institutions so doesn't have the same message volume as retail facing.

What language do you think validators run? So much stuff that makes absolutely no sense..

Order sequencing is not opaque, that is one of the primary benefits of DEX that aren't decentralized. SOL has issues with sequencing but there are attempts to fix this (Jane Street is one of the places working on this). This is a point that I made above about block space, and isn't relevant for Hyperliquid.