The TOK prescribed title #5, about the multiplicity of therories, while it is easy to argue for one side, how do you argue for AGAINST it? (entire point of TOK essay to provide as good counterarguements as arguements?)

“Given that every theory has its limitations, we need to retain a multiplicity of theories to understand the world.” Discuss this claim with reference to two areas of knowledge.

Well obviously we could all pull up examples where several therories are used in pretty much every AOK, ethics, human and natural sciences, etc. It is too easy.

But how do you argue against it, that is saying that we DO NOT need to retain a multiplicity of therories. The question makes "every therory has its limitations" as a given, so how do you make counterpoints to this? How do you argue that we should not have a multiplicity of therories so that it does not come off as lip service or obviously fake?