It depends how the line is set - typically they are slightly angled so the committee boat is favored.
I thought that most Race Officers favoured a Port bias, so that boats would not bunch up at the committee boat end of the line and cause mayhem
exactly. spread people out oon the line.
My reading of the guidelines is 1 and 1/2 boats of room per boat in the start
Me too
Another common situation is the one where a windward boat is about to be pushed over the starting line by a leeward boat. Leeward hails "up up up" while the windward boat replies "Hey, you are pushing me over" and stays put.
to which the answer is - "Your problem, not mine"