Due to the hectic schedules, & a lot of technicalities in shooting, television people often opt for different units/ double shifts & simultaneous shoots. Thus they at times have two directors or even more as to make things flow smoothly.
I personally don't think both these directors are shooting for any specific family. It probably depends on their availability. Yet I agree with the people who mentioned about Arshad being great at Romantic scenes & LM in my opinion does wonders to suspense & making scenes more edgy n powerful. He almost reminds me of my shhh koi hai days