Members often ask about environmental conditions on grass days, esp in winter months. I always point out activities such as rugby and TA where people meet on Sunday morning out in fields and get cold and wet while exercising and getting sweaty. Indeed, right next to our dogging car park we have the local football team meeting for their day on the grass.
MA were developed and fought out on grass in all conditions - we are simply going back to the roots - the roots of the ryuha as it were.