YOU HAVE IT LITERALLY BACKWARDS.  FLOODING COSTS LESS IN COORDINATOR FEES THAN CONSOLIDATING, GIVING SYBIL ATTACKERS AN UPPER HAND OVER HONEST USERS:

Let's say you have 10 million sats.  If you flood the 1 million sat pool with 10 UTXOs, you pay 100k sats to the coordinator.  If you only create 2 UTXOs and participate in the 5 million sat pool, you pay 175k sats to the coordinator.  THE FLOODER PAYS LESS TO THE COORDINATOR THAN THE HONEST USER.

You still haven't even made an attempt to address the main issue which has nothing to do with Whirlpool's backward coordinator fee incentives - the REAL issue is how premixing needlessly consumes block space while HARMING the privacy gains of coinjoin participants:

https://image.nostr.build/14026e01cbbd0981d24e2b4866265f026b92bc584d9e2dc16acf1d641a4b69ef.jpg#m=image%2Fjpeg&dim=1544x1491&blurhash=%7C8SF%40R%25M%7EqMy%25hgLogt8wgtRM_D%25xvR%24xv-qV%40oNxbbakCoLR*aejZWUj%5Bxuj%5D%25MWURQWANFoMW-%3FcMxIU%25gNFWExuRjRkM%7BX7xbnQR%2BbEWBX7spf%2CxakBIonjazWBxHNssEt7kCRPtQV%5BM%7BxuRjIUof%25LRkV%40oeWCWAog&x=3226e49be19cf5640fddfd6ca3bccf5b980d5202c66abdcbe16ee69572319df1