Amazon Affiliate Content Structure Query

I'm looking for some advice on the content structure of an Amazon affiliate site.

Completely making up these keywords as an example to demonstrate my question.

Imagine the main KW is "best lawn mowers" therefore I would like to write a pillar article focusing on this keyword.

Do I include related keywords like - "best lawn mower for sloped gardens", "best lawn mower for small lawns", "best lawn mower for long grass" in the main pillar articles as sub sections?
Or do I create the main pillar article solely on the main KW and then 3 separate supporting articles for the related KW's?

Thanks in advance!

Second option sound more better to me.

I would have said the first option but could be wrong. I am not in a mainstream niche but when i target a keyword i also add the different words to pick up all the long tails

Hmmm - 2 contrasting responses! Thank you for your input though.

Anyone else have insight?

@aletissier a.t.m. I am researching as much a possible about Amazon Affiliate sites. One of the resources I bookmarked is this one;

https://techtage.com/amazon-affiliate-niche-site-guide/

Another great source, at least in my opinion, is this one;

https://nichehacks.com/structure-niche-sites/

Hope that helps answer your question to some extent.

Now I am no expert but here is what I am going recommend having a "Best Lawn Mowers" post\article is a bit too broad. what I would do is instead create a page Lawn Mowers where I create articles "Best Electrical Lawnmower" , "Best Small Lawn mowers" etc. And there include a post like "Best Lawn Mower 2018" which includes the overall bests since even that is a bit more specific than just "Best Lawn Mowers"