The routes on walkghighlands are not infinite, but rather a collection of over 2000 walks that the sites authors have been on. One of the brilliant things about the site is the fact that the site owners have actually been on the walks, and so are able to give a unique insight which you can't find on the map. I will point out that Paul and Helen are only two people!
Scotlands hills have infinite variations of hills you can link up or not, and nowhere is there a fully comprehensive list of all the routes that are possible - that would be a pretty tall order!
Why not go on a navigation course, or get some map skills yourself? That way you can make your own decisions about which hills would be good to link up. Far more satisfying in the long run