This is the sort of conspiracy nonsense for which the question: "to what purpose?" was made. Had the elves truly desired to rule Gondor then claim could have been made by Elrond; brother of Elros, first King of Númenor; Arwen; daughter of Elrond, niece of Elros, and future wife of Aragorn and Queen of the West (and other sundry titles); or either of Elladan or Elrohir; sons of Elrond and nephews of Elros.

It is also telling that within only a few generations all elves but those half-elves that had embraced their human side had left Middle Earth entirely, what need they for puppets?

It is also important to note the incredibly long lifespan of King Elessar Telcontar, also known as Aragorn. He lived 210 years, reigning as monarch for 122 years! Clearly he had some elf blood in him, thus strengthening the claim that he was of the line of ancient Númenor.