Sentomaru blocks Kizaru: Kizaru is a fraud (although Sentomaru did get defeated)
Kizaru blocks Base Luffy (he blitzed Ulti and Page One, but lost to Kaido): Base Luffy is a fraud? (I mean, his powerset revolves around his haki and his devil fruit so that kinda makes some sense, also, Kizaru might lose to base Luffy putting him below Lucci, I'd advise the admiral fandom to keep their standards low)
Also, I don't think it's unreasonable to believe Kizaru stomps Ulti and Page One at the same time