What settings are you using that causes 4 planets to touch another?  I haven't seen anything like that in my games, but maybe I have missed an extreme combination.

another thing is to force it to another spot I believe if you park a fleet in the spot it normally ejects it looks for a open spot.

I am also very curious what settings you might be using, as I've never seen anything like this either.  It's not a custom map, is it?

I am using a edited file to create a truly insane campaign and see what my computer can really do. 100 factions, 1300 habitable planets, .03 stars tripling the amount of systems, tripled the amount of other celestial objects, and more bonuses for rival AI factions.

MapSetupDefs.xml, <Stars>0.3</Stars>

GalCiv3MapDefs.xml, <ReduceStarSystemBoundarySize>1</ReduceStarSystemBoundarySize>

MapSizeDefs.xml, <MaxHabitablePlanets>1300</MaxHabitablePlanets>, MaxHabitablePlanets>1300</MaxHabitablePlanets>

Were the commands affecting the star and planet placement I think, this increased the number of stars and planets and reduced range between stars. I used this command to make the cluster map act more like small star clusters separated by large dead areas of space making station and logistics more important in the campaign.

I tried using the command offered Horeemvore, it worked perfectly.

Working on making a cheat map using the rat race mod to see how large of a system i cam make next, should be a fun learning experience modding files.

Here is part of a very good solution..... but your ship will always pile on top of your own ships, therefore.....

park a ship to block the normal exit and then sell that ship to another race! That should solve the problem.