Lu Li didn't send Ye Cha out to command those surrendered families. Yu Huashen alone was enough as he had the power and methods, being an overlord himself in the past.
Lu Li had other plans for Ye Cha and the others. The four patriarchs were secretly sent out. What they needed to do was to search for information and have the intelligence of the entire Northern Desert in their hands.
Lu Li could use more hands. Unifying the Northern Desert wouldn't be the most difficult thing. However, he wouldn't rest his mind until he had all the information he could get.
The Cyan Phoenix Race's speed was horrifying, and their assassination skill was well-known in the world. Sending them to collect intelligence was actually making them underemployed. Also, Lu Li had given them Illusions Masks which could facilitate them to go in and out of the city freely.
