Yeah people stacking when they shouldn't has been an issue.
I had a tank ragequit on me because we only stacked two people max, he thought you required all four or sonething. We did it fine with 2, healer was happy they didn't need to esuna as much, but when we eventually wiped for unrelated reasons he cussed us out and dropped. We kinda laughed him off and found a killer pld right after and had a blast farming without issue.