If the defendants are numerous, the court upon motion or of its initiative, may order that service of the pleadings of the defendants and replies thereto need not be made as between the defendants and that any cross-claim, counterclaim, or matter constituting an avoidance or affirmative defense contained therein shall be deemed to be denied or avoided by all other parties and that the filing of any such pleading with the court and service thereof upon the plaintiff constitutes due notice of it to the parties. A copy of every such order shall be served upon the parties in such manner and form as the court directs.