Case 9:6ase-doFeeKaMdsebd eR aaumentieaaon tied 9 Heeldet oFage2b 26 1 Page 3 of 10 on the part of the movant, . . . undue prejudice to the opposing party by virtue of allowance of the amendment, [and] futility of amendment.’” Laurie, 256 F.3d at 1274 (quoting Foman v. Davis, 371 U.S. 178, 182 (1962)). In addition to considering the effect of amendment on the parties, the court must consider “the importance of the amendment on the proper determination of the merits of a dispute.” 6 Wright & Miller, Fed. Prac. & Fed. P. § 1488, p. 814 (3d ed. 2010). Justice does not require amendment where the addition of parties with duplicative claims will not materially advance the resolution of the litigation on the merits. See Herring v. Delta Air Lines, Inc., 894 F.2d 1020, 1024 (9th Cir. 1989). A. Rule 21 Motion Jane Doe 3 and Jane Doe 4’s first attempt to join in this proceeding was brought under Rule 21. (DE 280). “If parties seek to add a party under Rule 21, courts generally use the standard of Rule 15, governing amendments to pleadings, to determine whether to allow the addition.” 12 Wright & Miller, Fed. Prac. & Fed. P., p. 432 (3d ed. 2013); see also Galustian v. Peter, 591 F.3d 724, 729-30 (4th Cir. 2010) (collecting cases and noting that Rule 15(a) applies to amendments seeking to add parties); Frank v. U.S. West, Inc., 3 F.3d 1357, 1365 (10th Cir. 1993) (“A motion to add a party 1s governed by Fed. R. Civ. P. 15(a)... .”). Rule 21, “Misjoinder and Non-joinder of Parties,” provides the court with a tool for correcting the “misjoinder” of parties that would otherwise result in dismissal. Fed. R. Civ. P. 21. Insofar as Rule 21 “relates to the addition of parties, it 1s intended to permit the bringing in of a person, who through inadvertence, mistake or for some other reason, had not been made a party and whose presence as a party is later found necessary or desirable.” United States v. Com. Bank of N. Am., 31 F.R.D. 133, 135 (S.D.N.Y. 1962) (internal quotation marks