My guess is that the tiers will be preset, like 1000, 3000, 5000, 10,000 gears etc will get you to the tier levels. And it sounds like you either don't lose gears for a loss, or if you drop below a tier, you still qualify, but may have that much more work to get to the next tier.
That is sort of how the old conflict system worked. 1000 points unlocked a unit, 2000 more got it to level 2, and so on. Your score relative to others didn't matter.