To give some futher advice on this and remember that this is not specific for this tactic but just some generall rules
If you are a top team and face deep sitting opponents, then the Deeper and more defensive MC ( if chosing one on defend) will see more of the ball when struggling to stretch the opponent. Here, its pehaps better to use both one Support or use one of them as a deeplying Playmaker/support ( and actually use a creative player here)
If on the other hand you play as a team where the opponents are more likely to push up and attack you, then you will be able to get the ball into adnaced positions more eaily, hence the play will not be dictated deep down the field so here, one MC on defend might be great.