We’re treading ground that’s been pretty thoroughly covered earlier:
One rule change that I would support is to bracket the tournament by player level, say 1-20, 21-40, and 41+. Level is a kinda okay proxy for overall bench depth, including a variety of 3* and 4* heroes. Having a good mix to choose from really helps in wars.
Bracketing players by level would then give newer players a reasonable shot at some decent loot, competing against other, similarly situated players.