You pick a ship but then in the group all ships are picked again, they need to relate to each other, either in the same event as a sub event or send the picked ship through a function as a param.
I reworked it with a bool that changes for the picked ship, so you can see it act on spacebar press :https://www.dropbox.com/s/mi5xp98xm31fp9s/alternating.capx?dl=0