It's 40k, not apocaplyse.
"ALLIED FORMATIONS
Formations do not count as your army’s Allied Detachment, even if they are made up of units from a different codex to your Primary Detachment, and they do not stop you from taking an Allied Detachment in the same army. However, the Levels of Alliance rules from the Warhammer 40,000 rulebook do apply to them and units chosen from a different codex that
are in the same army."
Soo....ok, this is just stupid. Why WOULDN'T YOU DO THAT? Every Tau player (except me) thinks it's all about Broadsides and Riptides. Why wouldn't you want them to have Tank Hunters and Preferred Enemy randomly, just because?
This is random and stupid. There's no way we can really consider using these little $4 cheat sheets, especially if there's going to be 25 of them by Christmas. They're clearly beer & pretzels, fluffy, not much thought given sorts of rules. These are not meant for competitive play. Even less so than FW.
Why even have a Force Org chart anymore? Just take whatever the hell you want! It's no longer a game, we're just throwing dice and pushing models around.