$25 cuts way to low. How many square feet these property's?
10 lawns solo
14 with two
I would think you should do better then 4 more lawns with two men.
You are doing 40 lawns a day now and you largest mower is a 36".
Forget getting a 2nd 36". You need to increase production capability with a larger mower. 48", 54", 60", before you add a 2nd employee.