Ye Wudao didn't actually kill them. He just frightened them and then let them go. These were just small fries, and without them, other business spies would emerge.
With the expansion and rising fame of Shenzhou Pharmaceutical Company, there would only be more business spies, not less. The most important thing was for Ye Wudao to make Shenzhou Pharmaceuticals impregnable, deterring those with ulterior motives with formidable defenses rather than killing every intruder one by one or two by two. Ye Wudao wasn't a murderous Demon King—if he were, he probably wouldn't even have time to go to the toilet.
After dealing with the matter of the foreign spies, Ye Wudao finally breathed a sigh of relief, but he still didn't dare to become too careless. Wherever he went, he took Zhao Xiaoman with him, determined not to give the enemy a chance to harm her.