I face this situation today. During the 3rd period, I was down to 2 Bruisers and there were on the board. My friend ask whether I will be immediately eliminated if he manage to kill another Bruiser by the time the 4th period begins. I still have my Runners with me but I will not be able to field enough figures if the the 3 Runners and 2 Bruisers requirement needs to be fulfilled. So would I be eliminated when the 4th period begins?
Do you still have a ringer? You can sub a ringer for a bruiser.
But yeah, if you can't field 3 runners and 2 bruisers at the start of a period, you auto-lose