97 of the 106 were named. The others weren't accused and arrested on or about May 17. They aren't named because they haven't been arrested yet, and the state doesn't want to give them notice of indictment until after they have been arrested.
My impression of the priority order given is that those indicted this past Tuesday were members of certain clubs (or gangs, if you are on the state's side of this dispute), and those not (yet) indicted are members of different motorcycle clubs (or gangs). That is the difference in evidence.
The state's legal theory amounts to conspiracy by association. Prior agreement to perpetrate assault is inferred or bootstrapped from the fact that assault occurred.
If you studiously ignore the all available evidence that runs counter to your supposition then its not hard to see how you reach that nonsensical conclusion.
60-70 Cossack MC members and their supporters arrived at Twin Peaks from all over Texas over an hour before the start of the Texas CoC meeting and took over the area of the restaurant reserved for that event.
Cossacks and their support clubs are not CoC members, their coordinated action that day was NOT just a coincidence, and folks who claim otherwise are full of it.