3/day.
Problem is that short rest is not that short.
In 4E short rest was short. 5mins is a breather. 1hr is a breather, a meal, a shower and a 15 min power nap also.
If you can get 1hr out of danger in 90% chances you can get 8hrs out of danger. So why not take the best possible rest option.
5min breaks were used even in medieval battles with front line rotation as no one could fight for more than few minutes at a time without some rest.
Cut down little on short rest power curve and make it 5min long and there will be room for it.