It would depend on what they're asking imo, if they are asking something like :
To what extent did the ... developments within North Vietnam lead to conflict or communist victory or something like that
I would write about the importance of developments and do a body paragraph on each section meaning 4 bodies which is ok. I've seen heaps of exemplars with more than 3 bodies but I usually do 3 because it's easier to scaffold ur essay if it's smaller and 3 is enough to get 23 or 24 consistently.
That DP kinda sucks for an essay tho, I doubt a question would be on it - even if it is you always have another option which is prob better unless it's about Cambodia and Laos.