Authority/Multiniche or Small niche related

First of all I am sorry if I didn't post in the right category but this one seemed right for my question.

I have several ideas and keywords for an informational and affiliate website, I am also not new to the SEO game but I did take a loong 4 years break when a lot happened.

I havea lot of researched keywords and I am willing to start working but I don't know how to structure it, given the google EAT update that scares me a lot, should I do a smallish website about how-to's and buyer guides in a small hardware/electrical field where I have experience (but not a degree or school-knowledge) or incorporate all in the big multi-niche authority DYI website that I am building?

TL;DR: Should I make a dedicated website for a small niche or incorporate that small niche in a bigger and diverse website that I am building (something like instructables or thespruce do).

1. I think having dedicated sistes for small niches will be more spot-on but also smaller and less brandable;
2. Even though I will do everything Whitehat, don't keep all your eggs in one basket right.

It is recommended to have more than one site so that your income does not dies in case something happens to one site.