All that's rolling at the moment is that
1.
USR that affect units if one model has it is still legit within its defined limits
2. Chapter tactics only cease to apply if two different sources of chapter tactics (in the sense of Codex: Astartes Chapter Tactics bonus rule ) are in the same unit.
Since 1 applies as standard and 2. isn't affected since
SW don't have a Chapter Tactics bonus rule, I think you're clear