Effectively they'll all miss each other. There is so much empty space in between stars that even when two galaxies collide the stars will interact gravitational

Effectively they'll all miss each other. There is so much empty space in between stars that even when two galaxies collide the stars will interact gravitationally, but likely none will physically collide. Think of two clouds of gas colliding. The clouds as a whole collide, yes, but there's no molecular fusion happening. The molecules themselves don't collide. "Pass through each other" is not the clearest wording.