Polo Rules

Cool, I think that's where I read/heard about it. I understand why they do it, it's open to abuse, but ref can easily turn the ball over for abuse.

Although, I don't really know what would happen if subbing was going really slowly... Ref calls game on and they deal with it?

There's a reason why we stop the clock in 3 vs 3, and it's just as good a reason in BM. If one team is taking too long over subs, ref can penalise them (ball turnover, delayed penalty).