well... when a train moves, it does as a whole (like my train along the tracks), but when it reaches it's destination it also stops as a whole (which mine doesn't,in my case each carts has to reach the destination before turning around). but because of the way my train works (moving from node to node) i can't just pin it together, or it would look all sorts of wrong, and won't work, please try it and you'll see.
maybe there is an alternative solution for the "moving along the tracks" thing that didn't occur to me. i couldn't make it work with pathfinding, so i had to make it with a self made movement.
any solutions for this would be really appreciated. i'm kinda stuck with this =(