To each their own, I wouldn't optimize multiple pages of the same site for the same keyword.
You don't optimize multiple pages.
(Proper) optimization means:
- putting keyword in titlte
- in h1, h2 tags
- in img alt attributes
- making it appear at the very least once inside your content.
All you do here is insert it in the <title> tags so that only Google reads it and it appears in the title bar of your browser, which is probably only visible when you hover your mouse over it due to length of title. It's a tiny tweak that can show great results, and it definitely won't make your pages battle for each other when the page you want to rank is decently optimized, onpage and offpage wise.