Build niche parasite on my own big DA website or use my a smaller niche focussed website?

Let's say I want to rank for "buy insurance".

I already have a tiny +6y aged website with some seo rankings for these keywords but nothing crazy.

I was thinking to use my other big DA website to rank on same keywords and use 2 websites to target that keyword.

I noticed health line creates a new article in a health niche and kills all smaller websites in those niches. So I want to do the same.

Do you guys think it will work well?

I even thought of using multiple websites to rank for a kw.

Currently I managed to place 2 results in top 10 (different niche). One high DA, other medium