In teh article "Our Collision With Andromeda Will Look Like This" You write; ".. the ultimate fate of our own planet when the Milky Way fatally.."

The probability of star-collisions in colliding galaxies a a billion to one they say.
So the chance of colliding planets are even more remote.

Most likely, outr solar system would be untouched. We could be stripped of some of the outer planets and most likely Oort's cloud.

But colliding planets? hardly
(I know the source (pparc) said the same thing, but that doesn't make it true...)