I do not know if this is happening to other players so I thought I would ask before I post on bugtracker.
https://www.wowhead.com/quest=53331/show-off The timer goes down to 30 sec before the 1st zeppelin comes out and in the remaining 30 secs there are approx 3-4 zeppelins that comes out. Jumping fences and stabbing the dummies did not take me to 300.
I have not seen players doing this quest anymore.