Actually, The Phantom Ranger was himself a knock-off character. The FREW company (named after the four fans who started in 1948) made a deliberate decision to use the Lee Falk's The Phantom as a template for new characters which were 'The Phantom Ranger' 'Sir Falcoln','The Aust Shadow' and 'Catman'. This type of mystery man seemed to appeal most to the Australian Audience. Frew is currently in the middle of a new serial about the Phantom Ranger (In Giant-size phantom comics) which has integrated the Ranger into the Phantom Mythos. And yes,'Walker's Table' features in this.
Link to the book: The Phantom Ranger 002
Well it sure looks like the Phantom Ranger is another Cloned Ranger, but if you say he's a Cloned Phantom, then I guess so. It's sort of a reversal of the idea where the Green Hornet is a modern-day version of the Lone Ranger - but I wouldn't include the Green Hornet in the list of Cloned Rangers. In this case, the Phantom Ranger is an Old West version of the Phantom (but the influence of the Lone Ranger is still pretty obvious, no matter what FREW claims).
I mean, there's "influenced", and then there's "Xeroxed"... Let's say the Phantom Ranger is a little less of a direct LR clone in that there was an attempt to mix it up by adding different elements to the usual Cloned Ranger (in this case, elements from The Phantom). Most of the Cloned Rangers aren't attempting to add ANY original elements to their knockoff version, although it's unavoidable to a certain extent if for no other reason than to avoid lawsuits -- and there were enough Cloned Rangers to keep The Lone Ranger Inc.'s (and before that, George W. Trendle's) lawyers busy for years if they had chosen to take them ALL to court. Maybe that's why there wasn't more legal action -- there was little to gain, and a mounting bill of lawyer fees to consider. When you consider that DC's lawyers were suing Victor Fox for Wonder Man, and Fawcett Comics for Captain Marvel, how much would DC have had to spend in legal fees to pursue ALL of the Cloned Supermen? Luckily it was easier to obscure the source of inspiration for superheroes in general just by giving them a few small tweaks.