I would not attempt to create cleavage with the forms you have.
If you go braless make sure all areas are covered. You don’t want the edges showing.
I would check your bra size. Are you wearing the correct bra size. Cup size and Band size.
If the forms are the proper size for your chest size and you are wearing the correct bra the forms should not be pushing together and being one mass.
Sorry I hope this helps in some way.