There aren't publisher-s; only Publisher.

A problem in a nutshell.

Remember -- these were once all separate publishers.  Publishers with their own editorial crew, that many more chances to try to catch on.

Now -- under the rubric of Penguin Random House.  Some big names.  One company.

Alfred A. Knopf
Ballantine
Bantam
Broadway
Dial
Pantheon
Random House
Razorbill.
Ace
Berkley Books
Crown
Del Rey
Doubleday
Dutton
Gotham Books
Grossett & Dunlap
Hudson Street
InkLit
New American Library
Penguin
Philomel
Plume
Price Stern Sloan
Puffin
Putnam
Riverhead
Schocken
Three Rivers
Viking.

Anti-trust would appear to be dead.