more than 1 object per gravity well?

lo everyone out there,

im fairly new to this game and was just wondering if i would be able to modify the existing
gravity and phase space system.

what i want to do is quite simple:

have 1 sun with a large well around it where other planets can be placed within.
have asteroids near planets and wormholes etc all without a seperate "zone" around them
so there would be no need for phase space - just one big zone to freely roam in

can someone enlighten me on this please?
i have no problem wasting hours in config files, just need to know if this is possible/solved/not doable at all.

thanks for reading - have a nice day

ps. sry 4 syntax - foreign language and stuff ..