Ive been at site x's position and y position and traffic wasnt much better than where I am now - maybe 35 clicks a day rather than 20 or 30.
S.P.A.M. = Sites Positioned Above Mine
First, I'd probably file a spam report on sites x, y and z since it's all the same company.
I've been there and done that with one of my competitors that tried to use about 50 cross-linked domains to dominate listings and Google turned a few knobs and dials and suddenly the competition was more fair.
More importantly, why are you struggling on that single term?
I used to bust my butt to keep one single word where I was top 10 in all major SEs for years and it only contributed 3K visitors/mo vs 400K/mo in long tail searches.
Gave up that keyword and never looked back after easily dominating the long tails in my niche that surprisingly drove way more traffic.