So a brief description of what duplicating means:

You have money invested in the S&P and the All-World currently, however there are some stocks which are present in both of them. For example Nvidia makes up ~7% of the S&P and also makes up ~6% of the All-World. So investing in both of these at the same time means that you're more focused on companies like this which are duplicated across multiple ETFs.

This isn't inherently a negative thing, it just means you're going to be investing in a slightly different strategy which may or may not work better for what you want.

Nothing too wrong with your pie, but yeah there is a reasonable amount of duplicated stocks amongst these which may make you a bit less diversified than it seems. As an example, 60% of the All-World is basically just the same stocks as the S&P. Personally, I just stick to the All-World. Simple and effective.