One of the many reasons for my nickname

Dakiras: What Wing said. Mediums are great fun to play.   OP is right in saying that flanking is not simply peeking from behind a building and screaming "BOO!" That's not actually flanking, that's peeking. Flanking is rotating your mobile forces around enemy positions to gain advantages. To say that this is not a possible strategy to execute is going a bit far. Difficult, but not impossible. It does require some trust that your team will be able to draw enemy fire, avoid hits, and survive the initial onslaught of shells. Then when the enemy is suitably distracted and out of position, you attack their exposed sides (the flank... y'see where I'm going with this?) That's flanking. That's how it worked with with cavalry back in the day, and you have to consider Mediums to be similar to cavalry. Mobile, heavy-hitting machine of death-ness taking down the long-range or less mobile units before slinking off into the sunset.   At least that's how I personally view Mediums, and that's how I generally play them. I might be wrong, so others may correct me, but I think it's rather fitting for the type.