Strangely there is quite a few there I don't remember (Supercar), a number I only vaguely recall (Journey to the Far Side of the Sun) and a couple I'd rather not remember (Joe 90).
If I remember rightly, at the time The Protectors came out there were a huge range of other 'The's' about. The Champions, The Persuadors, The Avengers, The Saint, even Randall and Hopkirk all offering much the same in quick succesion. The Protectors got lost.
There are few writers/producers that have such a huge range of different show styles under their belt as Gerry Anderson. Which shows how gifted he is.