Substitution Question

[mrm21711]

A is the DH and batting in the 5th spot in the lineup. B is pitching and A is batting for him as the DH. Player C is in left field batting in the 7th spot.

If player D comes in off the bench to pitch and player B goes to left field, can these be treated as intersecting substitutions (manager has the option of placing player D in either the 5th spot or the 7th spot and vica versa for player B)? I understand this terminates the DH and if the previous pitcher goes to play defense, the DH role is terminated and player A is removed from the game.