Non-stop.
Instead they went for a single big simultaneous attack, leaving them open to a counter attack, and even if that hadn't happened, they'd get in each others way and they probably would have stopped after their big attack, instead of fighting strategically, letting the others rest while 1 or 2 of them keep smashing in Muzan's body.
It was 100% dumb emotional attacking instead of strategy. Hashira should know better.