The ship’s mass being that of the faster-moving ship. That way caps bouncing off each other when they jump through cynos can shred each other.
Congratulations, you’ve just cited video game physics and claimed it is greater than I. How about a little bit of real physics, since they’ve tried to explain things in a way that makes sense?
Is there any such thing as an infinite-strength anything? Nope! Everything in the universe is finite, even the speed at which you can travel through a certain space. Even black holes, they don’t reach “infinite” gravitational strength at the very center of whatever is in their centers… it’s just a REALLY big number, which even if it has a potential maximum will still not be infinite.
Good example, two magnets. Can you touch repulsing poles together if you just push harder? Yes, you certainly can. You just have to push harder. Can a planet currently held by a star’s gravitational field be push out of its influence? Certainly.
Ergo, bumping, even with psudo-physics answers that you’ve provided, can still cause damage when the kinetic potential exceeds the repulsive potential.