To answer the question seriously it's all but guaranteed to me that Dragon will act first. Though this really depends on what the question means
Who will do something in the story first or who will get good "feats" first
One will satiate the powerscalers that's for sure
It was serious quesiton tbh.
Back pre-ts people thought differently, but like any old chracters people waiting "named attacks" he been so dehyped im nto sure anymore
Like before i would paid money he gonna move last against FV out of all characters before luffy.
But now? Eh, with how oda writing even roger i dont think he is doing anything really relevant tbh. Like yeah it might be a big "feat" in the context of that chapter but its gonna be nothing noteworthy EoS i think