Well the stats don't matter at all currently... there are enough weak players even in top 100 so you don't need much to win battles. And it doesn't seem that you need any $$ to get max stats, the best girls girls all come from the missions/drops, best equipment can now be obtained from contests, and shop stats just take a lot of cash to max out.
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Also apparently other player stats are intentionally lowered when fighting them? When I check my own stats in the tower they're much lower than my actual stats (the amount of charm/hardcore/know how is the same, but attack/defense are way lower), and if I fight players that have similar equipment/stats I beat them by a fair margin. What stats are considered "high"? Here's what I got right now:
It's quite a shame that a major part of the game has no purpose at all.