Ooh, could be. There are all kinds of times something like that could be useful. Maybe he wanted Matt to be able to act like Mike too, but obviously that will be more difficult for him, acting like he could see, so mostly it's Matt's personality they are working with and Mike had to spend a lot of time basically being Matt in various situations. Which could lead to some resentment, actually. But it also meant he can do a very very good impersonation of his brother. Good enough to fool Foggy.