Resource drops are probably ok or only need minor revision since they scale with AP and get a % increase per tier. Fragment drops on the other hand need some major revision, as T1 and T5 hardly have any difference since AP doesn't effect fragment drops whatsoever.
Example (with 0% drop rate added in equipment):
T1: 1 frag always, common to godlike, slightly lower than current rarity chances*.
T2: 1 frag always, ~50% chance for a second, common to godlike,same rarity chances as currently set.
T3: 2 frag always, common to godlike, same rarity chances as currently set.
T4: 2 frags always, uncommon to godlike, higher rarity chances.
T5: 2 frags always, rare to godlike, even higher rarity chances.
Rarity chance: chance of getting higher rarity such as godlike over a lower rarity such as common.
As for drop rate items, they wouldn't really help in T3 or above any more, but I imagine most people are packing down on drop rate for pvp anyways... I suppose if that was considered important than the frag drop rate could remain the same as it already is but the rarity found in each tier could be modified to scale better (lower than now in t1 and t2, and higher than now in t4 and t5).
Of course this all still leaves the horrible gear issue where you need seriously good gear to be successful in pvp in tier 2 or higher. And if t1 drops are nerfed significantly, than it'll be harder for people to get into pvp since they will have a much harder time gearing for it. Of course, that's only a problem because epics/godlikes are so OP currently (or more specifically, high level maximum geared units are OP). Gear OPness has driven me away from the game (pvp specifically, which is mostly what I did, so yeah...) more than anything else. Race and unit balance still isn't perfect sure, but they are more like the icing on the gear cake.