What you pay your employees an hour in the big picture is irrelevant. What ever minimum wage is add 30-50% to that and thats the starting wage. No one is going to do a hard job for minimum wage when they can get an easy job for minimum wage. McDonald's starts around 10 an hour here so we must start around 12-13. Do I feel the guys are worth that today nope but I have competition for workers not just from landscapers but from every other entry level job in the area. And this generation wants it now and do not want to work for it so they almost always break towards whats easy.
Now I have no idea why the op thinks an employee will boost him from 10 lawns to 14 a day. Those numbers are so low as to not be worth doing it. I run two 2 man crews and our numbers look a lot different 50-70 lawns per day or an average of 25-35 lawns per 2 man crew per day.