It's a shame the TR story isn't here, but at least we have the excellent Silver Starr.
Silver Starr is actually a pretty amazing simulation of the Alex Raymond style. Seems like they tried to take it a bit more in the fantasy direction than was usually the case with the genuine Flash Gordon.
On the other hand, you've got Twilight Ranger, who judging by the other covers you showed, they attempted to keep just as close as they could, with as little variation (down to the uniform color and the faithful Indian companion) on the Lone Ranger as possible. I've always wondered what publishers are thinking... probably something along the lines of Victor Fox's infamous quote (when asked to justify the sex and violence in his publications)
"There are more morons than people, you know!"