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I hear the same kind of argument for playing these decks all the time. "I want to play a deck that gives me opportunities to outplay my opponent!" You know what else does that? Virtually every deck in Magic! You don't have to be playing with a pile of blue instants in order to win games based on the decisions that you make.
Now, it's certainly true that playing a deck with a lot of spells can frequently give you an edge over less experienced players who won't play around them. If your opponents are going to attack with all of their creatures or cast all of their spells into your open mana every turn no matter what, then of course cards like Unsummon and Azorious Charm and Syncopate are going to overperform against them.

But are they who you're really worried about beating?