I was playing against a passing oriented Chaos team the other day with my Orcs.
I managed to score in 4 turns, followed by him scoring in 3. I have to admit, I saw the ag4 beastman with pass, but I really didn't expect to be playing against a 4 downfield reciever set with a Chaos opponent, hence the sloppy D on my part.
Anyway, start of the second half, I'm kicking, score is 1-1.
The KO result is PI, and he gets 4 KOs and 1 BH.
I swarm the ball and by turn 3 I could easily score. Which would most likely leave him back with 11 players and 4 turns to score to tie...
So I stalled. After knocking all his players over he didn't stand them up, and I didn't bother to foul - no DPs on my orc team at this point.
Finally realizing I was going to wait to score at the end, he came after me with that ag4 beastie, dodged through 4 tzs to throw a 1 D block - POW of course

.
Well, this is my turn 7, and the ball bounces out of bounds of course. Fourtunately, the ball ended up still near his end zone, and I managed to pick it up and score on T8 anyway. Had he not left most of his players on the ground and really gone after my ball carrier, he most likely could have forced me to score sooner, or perhaps even stopped me from scoring.
Anyway, stalling is a valid aspect of defense, pure and simple. In my experience, 90% of the time a team can stall is due to soft defense on the opponent's part, and well, the other 10% is no different then any of the myriad other ways Nuffle can abuse a coach.
I go into a game expecting that my opponent will try to win, and frankly would be disappointed if he did not. I expect, given the chance, zons to dodge away, elves to huck the ball from one end of the field to another, skaven to leave my players in the dust, and power teams to play smart clock management.