If I was in this position, I would probably attack this problem on a two part approach.
First I would analyse the top 10 or 20 results of each of these competitors.
I would see how many social shares, back links, topical flow, and pages indexed the site has.
From there I would then see if the sites are coming up quickly and track their ranking, I would try to replicate each of the top 10. Get as close as possible. And I would make a 11th or 12th that is a mix of what you consider the best of the first few.
See which one hits.
The thing is, if you start with a simple way to do it for one, you can do it for every niche. So instead of focusing on how much work focus on making it so it can be done for each niche as you decided to grow or keyword.
Another thing to note, is if you notice churn and burn is working, there should be no reason you shouldn't deploy some churn and burn sites your self in the niche. While you keep working on your money site.
Just this takes more time, so which of the two is more important long term, or short term. Neither, both