Coordinated payout aren't against the ToS nor is using third party apps to communicate (as far as I know).
"Shard mafias" have been debated a lot and I very much doubt anything can be done other than what you can do for yourself. Reach out to them and try and establish other players' payout times and see if you can reach an agreement with them. A higher risk alternative is to make a pest of yourself but these group may have 25 plus people in them so the numbers are stacked against you.
Sorry but there really isn't much more you can do.