Generally as the tiers increase, the hero fragments increase. But for Challenger (750 to 999k), everything top 15% and below is actually worse off than the tier directly before it. You get a wee bit more energy but that’s not enough to justify the drops. It’s also inconsistent. You cant convince me that it’s anything other than a mistake in balancing when there is no precedent or justification whatsoever in the prize structure. All the other tiers dont have this weird fragment drop when u improve your tier regardless of whether extra useless stuff like PVP gems, cash or energy is given out to compensate.
It’s the most unbalanced and unrewarding tier and you really have no reason to upgrade to it or stay there. Stay in the lower tier or upgrade straight to the 1M tier. Otherwise, make sure you get top 7% minimum every time.