While I agree that Fleet Mafia is a problem that needs to be addressed, forgive me for saying this but, your ideas are simply awful. Because:
- GP, is a measure of your roster completeness not the actual power... By your logic, a 500k Endurance fleet would result stronger than an 400k Executor fleet, which is not the case.
- Skill level? This is not a chess game, There is no skill involved here. In Grand Arena, you win either by having a stronger roster or by having the right counters.
- The Grand Arena is already a mess as it is, putting all the crystals there would further unbalance the game.
- Allowing an even easier access to payout times would give to some players an invaluable instrument to help them steal rewards from others.
One solution that could alleviate the problem is to remove reward times altogether. Simply track the player's best position over a 24-hour period. Then, even if a player only gets first place for a couple of minutes, they would still be entitled to the first-place reward.
Find a way to re-shard the shards periodically would be a nice to have, but it comes with an high cost, so it is unlikely that we will ever see that.