If you want to maintain the level balance between all the faders/channels that are grouped together you’ll need to use a DCA or an audio group assignment.
Using an audio group will let you add processing that groups of channels and if needed
a direct combined output of those channels.
If you do use an audio group you will want to un-assign those grouped channels from the
main LR mix.
If you just want simple one fader control of a group of channels yet still be able to
adjust channel by channel levels within that group a DCA would be the best way to go.