So, turns out the competitive Guardian Games Strikes playlist basically functions like a nightfall, so it's locked to the Lightblade strike.

This means you can simultaneously progress:

- Gunsmith weapon bounties
- Strike bounties (Zavala)
- Throne World bounties (Fynch)
- HELM bounties (they're for both the seasonal mode and Throne World, so basically a second set of Throne World bounties)
- Guardian Games bounties

If you have the app you can top up on all the bounties from orbit.