On Page SEO Question

Do you always need your "exact match" keyword at a density of 0.5-1% for good on page SEO? Or can "partial match keywords" assume their role?

Reason I ask is because my keyword is such that it would be unnatural to mention more than in the title tag and maybe once in body.

Let's pretend it was "tresemme shampoo bottle".

I have a picture, small description, and a link to a place to buy "tresemme shampoo bottle". Thats like 30 words.

The other 800 words of my article are on the benefits and overview of "tresemme shampoo".

So on-page I have my exact keyword only in title and in the brief description.

I do however, have "partial keywords" ("tresemme" & "tresemme shampoo") written 12-14 times naturally in the 800 word article.

My only competitor that I want to beat in my niche has his pages structured like this and I am trying to decide if that's an okay strategy or if hes just an idiot and is ranking because of how low the competition is?

So atm his page and my draft page that I have yet to publish looks like this (assuming our keyword was "tresemme shampoo bottle"

Page Length = 800 words

"tresemme shampoo bottle" = 2 times = title 1x and in body 1x
"tresemme shampoo" = 14 times = in body 14x

I am worried about over-optimization so I guess my questions are:

1) Is this okay on-page SEO? In this scenario can the "partial match keyword" assume the SEO role for my "exact match keyword" aka will google make the connection based on my title tag?

Or should I forcefully try and insert my "exact match keyword"
2 more times (it would be in 800 word article 4x instead of 2x) to make the density 0.5%?

2) Is having my partial keyword of "tresemme shampoo" in my article of 800 words 14x overkill if written naturally? Do the rules of keyword stuffing apply to "partial match keywords"?


I am probably over-thinking here like I always do but this is confusing me.