If khan picks firing line, he can make all of his teammates in a radius immune to stuns. That renders grumpy bomb and poppy bomb useless. However, this means that you can force him to use battle shout with grumpy bomb.
[Only Works when you use Legendary Card:Firing Line]
When BK throws his Grumpy Bomb try to stay near your team and activate your Q (BattleShout) to get your Team a 4sec CC Immunity and not get stunned.