Suicune should be at least higher than jirachi.
Suicune is much more dangerous.
Salamence and Metagross should be higher too, and Heracross deserve at least a mention.
metagross very rarely ends up being a huge threat on its own, since things like milotic, swampert and forretress are on every team
metagross cb can beat bulky waters, and it can also explode, removing the bulky water, so something like salamence/tyranitar would have a much easier time.
I have beaten milotics with cb meteor mashes before though (if it gets lucky with atk raises).
Sometimes a bulky water isnt enough to stop a Metagross, and it always risks an explosion.
Also, some time ago, I made a list about how i would rank the most common ADV threats (both offensive and defensive)
Big threats (not in a particular order):