How do I prevent sprites from overlapping?

I've just started attempting to make a tower defence game (with a single tower in the middle of the screen, and enemies spawning in to attack the tower).

I've managed to randomize the enemy spawn points, and using the MoveTo option I've got the enemies moving to the tower as soon as they've spawned.

I've set the enemies+the tower to Solids, but the enemies are still going inside the tower sprite. Is there a way I can prevent this?

This is what I'm using to move the enemy to the tower.

This is the enemy sprite inside the tower, despite both having the Solid behaviour enables.

Found a way to fix it. Probably an overly difficult method, but hey, it works :P

This is what I did

And this is it in play

If anyone is aware of a better method to do this, I'm happy to learn better ways