One thing you can do to mitigate this is basically:

* Line them up with your guys on follow.
* Move your main forward 20 yards or so just using your "move forward" keybind while your slaves just follow your main.
* Move your main backward 20 yards or so just using your "move back" keybind while your slaves just follow your main.
* Repeat several times.

What this does is causes the followers to "narrow" the angle more each time. It isn't perfect but I have used this in several fights where I wanted to constantly move the entire group around every few seconds.

Caveat: this doesn't work if you have to change directions during the fight or if you accidentally hit follow again. Basically, it will continue to work pretty good until you turn any character.

Hope that helps.