I should also specify that the points themselves shouldn't be in any specific order, just whichever is closest to Sprite 2 instance.
You should've mentioned this from the beginning.
The easiest solution would probably be attaching 4 invisible "Anchor" sprites to these image points - you can do this manually in layout editor, add them as children to the hierarchy.
Then you can pick the nearest Anchor sprite and replace it with Sprite2:
Sprite1 On collision with Sprite2
Sprite1 Pick all children Anchor
Anchor pick nearest to (Sprite2.x, Sprite2.y)
... Sprite2 set position to Anchor
... Sprite1 add child Sprite2
... Anchor destroy
Alternatively, if you want to do this with image points, you will have to loop through all image points, check which ones are unoccupied, and which one is the nearest to Sprite1 - the code for this will be pretty complicated.