Help with setting up silo structure

Hi guys,

Beginner at SEO, have taken a few courses and am setting up my first site. my market is niche specific DVDs in an online store.

I want to promote my products via content marketing.

After doing keyword research on trends/keyword planner, the most popular terms are like "best niche series 2017" "top 10 niche series" "best thriller/romance/drama niche series" "where to buy niche dvd" etc. Years are overwhelmingly more popular than genre.

So my question is... if I'm setting up my silo like: seed keyword to genre to tv show title

Where do the blog articles like "top 10 shows" "best shows of 2017"?

Would it be like:

seed keyword

· genre 1

· - show name 1

· genre 2

· - show name 2

· genre 3

· - show name 3

· blog

· - blog content 1

· - blog content 2

etc etc

Am I on the right track here?

domain/ category/ showname

domain/ keywordblog/ keywordarticle

Is this correct?

The other thing is, I have read one silo should not be more than double the size of another silo. Is this the case even with online stores?

Any help would be greatly appreciated.