I don't believe he is. You can't use A/B/C logic when comparing characters. Naruto, DSM Kabuto, and Guy are the best suited to fight a juubi jinchuriki because naruto and DSM Kabuto have mastered Sage mode and Guy has mastered taijutsu. It doesn't mean they are the strongest in general, just better suited for this fight. Keep in mind Guy is a taijutsu EXPERT, where as Minato used a sage mode that he had never used before and admitted he could never use in battle because he couldn't handle the chakra. Now is Guy faster than Minato with the gates open? Minus FTG I would say yes. FTG is INSTANT so nothing is faster than that.