People aren't really playing land destruction in standard, so its not a terrible idea to play less gates that don't support your heavier colors, and just play redundant copies of the ones that do.
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Have you considered playing more of the green based gates (maybe selesnya and simic due to your high blue/white mana count) and swapping Opaline Unicorn for Sylvan Caryatid? Has one more toughness, can't be targeted and costs one less mana.