MTR 8.4 Unified Deck Construction Rules

Team Constructed tournaments use Unified Deck Construction rules: With the exception of cards with the basic supertype or cards with text that specifies otherwise, no two decks on a team may contain the same card, based on its English card title. (For example, if one player is using Naturalize in a Team Constructed tournament, no other player on that team may use Naturalize in his or her deck.) No players may use cards that are banned in a particular format.

Unified Deck Construction rules are only applied when all members of a team have decks of the same format.