It looks like you have gotten some great responses and tremendous insight into the peroneals. My advice will continue to build upon those before me.
The foot and ankle complex is such a delicate area of the body to work with given that we are on them for so much each day. Particularly the peroneals, which act like a stirup that wrap around our lower leg and head into our toes to control the arches with each step that we take. Muscle imbalances somewhere in the body create a foot and lose its arch. The orthotics are a good idea because the ground reaction forces transmit energy back up through the entire body. Without them we had an ankle that flattened on impact, making the foot turn out, and the lower and upper leg turn in. Obviously that is a potential problem that the orthotics will help with. Just remember that the body is a chain that is adaptable.
With the orthotics in we still have muscles that havent been used properly and are at the incorrect length-tension relationship, meaning that corrective exercises to strengthen, stretch and foam rolling should a major part of a daily routine to reinforce what good the orthotics will provide.
hope thus does a little something to rejnforce the others,