On circle maps there are no 2 points that are sufficiently distant enough to warrant focusing. What you want to do is play a dynamic game of ring-around-the-rosies, trying to one-up your opponent's caps as you go around in a circle. I don't think I could explain it particularly well even if I was sober; it relies on your ability to read the battlefield and strike where your enemy is weakest.
Literally ring around the rosie is how I describe it, for especially bunker Come to think of it, Bunker is the only map I know that's like that. Larger circle maps can accomodate the "hold 2" strategy.
But for bunker, in pub games, simply taking the point that the enemy just took works, speed is key here, and make sure your team moves together and avoids pointless fights.
However, if they disrupt your little circuit, the strategy is hit them where they aren't. Pick the node that has the lowest number of enemies and overpower it, taking it quickly. Then move on to the next one.
For larger maps or that have points arranged in a line, pick two adjacent points and try to hold them is usually best. Keep in mind that verticality is a key part of Hawken, so if there are points that are on higher ground they are by nature easier to defend. From there, just make sure your team doesn't try to be too aggressive or stretch yourselves too thin.
If you try to play MA as TDM, you'll fail. So not only do you have to be on your game, but your team does too. let em know if they aren't.
Blah I just like to talk.