Make the investment and hire a professional writer to write your pillar posts. Expect to invest anywhere between $50 to $100 for a single pillar post.
And just rewrite the supporting articles.
If you want to rewrite your own stuff you can but you have to also realize this is a skill that will take some time to develop. Don´t expect to do a great job from the start. Just make sure your articles pass any plagiarism check before publishing them. After that, just shine and repeat.
I am myself on that boat as well.
I don´t consider myself to be a professional or a great writer but I do like to write a lot. And, I´ve been spending a lot of time reading and working to develop a writing skill that will be good enough for Google to rank my post high enough in SERP.
These are some elements I´ve found to be really helpful when writing/rewriting an article for my blog. I hope this also helps you find your way...
- Readability - Make sure to aim for a readability score of AT LEAST 70. There are many free tools available on the internet but my go-to one if the Hemingway Editor. You can download it for free here. There are other ways you can do to improve your article readability scores like writing in an active voice, keep paragraphs to a maximum of 3 lines avoid overcomplicated/technical words, make sure to drop your niche unique "jargon" into the mix,
- Scannability - Make the text as "scannable" as possible. This means, adding many visual cues to help the visitor read your content without actually having to read it. Adding many images, boxes (quotes, tweet this, info, warning, note, etc.), subheadings, summaries, random stats/facts. Also, bold/italic key phrases or words will also help scannability a lot.
Remember, mastering this skill (as with everything in life), takes patience, discipline and consistency. Keep rewriting your ass off a lot and in a few months you will be opening a BST here offering your services
Cheers!