
Gary L. answered 08/03/19
Patient and Experienced Tutor
I don't see why you can't bounce around between sections of writing so long as the finished product flows well. I am using a similar strategy on a piece I am working on writing, though I don't have any ninjas, sharks, ninjas on sharks, or ninja sharks.
In the end, be sure to review what you have written to see if it makes sense and flows well. It might be confusing if the hero fights ninjas on sharks and then later says they were samurais on dolphins.
Also be sure it is genuinely interesting all the way through. The first few chapters is often where readers are captured or lost. Write something that people want to read, not that they feel they have to read.