Support > DPS > Tank. That’s the order of priority as to who pushes the payload. Supports are usually in the backline and tank and DPS in the frontline. The tank should be the LAST person pushing the cart, they need to extend beyond it to make space. There are of course situations where that can’t be applied for one reason or another but usually that’s how it goes. Supports are usually in the back, so they’re the ones who usually sits on the payload.