Yes!!!

/stop (or /autostart off if you enable it before starting the level)
/nomovment on
/k all (if people moved)
/cstart

This magic combination solves all your problems. No need to run around and collect ammo any more. Remember that people started doing that to be fair, since there was no way to enforce people staying still at the beginning back then.

I think starting without ammo makes the start of the game a bit more strategic too... obviously the level needs to be balanced though. People who make levels should time the routes very carefully, so critical things like the seeker powerup are the same distance from both spawns. I think with imbalanced levels, it's probably better to start by collecting ammo.