yeah sure, cause gaining power is that easy. let's just empty our wallets to TRY and catch up with the top spenders of every server part of the bracket shall we...

No, it's not fair at all. You might think it's fair because you probably are among those who has power enough to actually fight back, but believe it or not, there are players who don't actually pay a whole lot (if anything) to enjoy this game.

People complained about Arena becoming cross-server, People complained about Matsuri being cross-server, I can get that, and yes, people got used to it because its completely random who you meet.
Sage wars was already something that worked BEFORE the cross-server was added, and here people can easily spot the weaker players by waiting for them to respawn.

Example of the fairness of this: a player with 30k power joins, he/she has a team-mate with 90k power.
same goes for another group, but how much fun will the 30k powered players have when they get constantly attacked by people with 3-times the power?

Point is, this was said to have balanced brackets, which it isn't. Balanced brackets would be having several sage wars that are individualized by power, for instance: one sage world for players with 31-35k, another for 36-40k, and another for players with 41-45k and so on. THAT is a balanced way to make sage wars, and everyone participating has a chance of winning some fights at least.

increase the gap by 5k more if the number of participants is too low, but that again could cause the very same problem it just got with power being too far apart.

Or they could simply make the Sage wars of the servers that COULDN'T meet their own quota be put into a cross-server sage wars, and leave the servers where sage wars already had enough players to their own server.