It depends on how much we want to change the system. If three ridings are combined, it doesn't correct much. I'm suggesting not combining them, but allocating the three seats while keeping the same ridings.
Henry Milner proposed 10 ridings for the Toronto region. Why combine the ridings? Let's keep the 10 ridings and one proportional. This comes back to what I was suggesting, which is to allocate MPs in a riding proportionally. However, your MPs won't have the majority in his or her riding.
There are mathematical ways to solve the problem. There are several solutions, in fact. The idea is to know what responds best to what we're trying to do that will be accepted by the public.