The Dunedain of the North and of the South

[Olmer]

Originally Posted by Eärniel

Without the protection and secrecy that Elrond's House offered, I doubt the line would have continued the way it did. Still, much was riding on Aragorn, if he came to perish, that very likely would have been the end of the direct line.

All right. Elrond kept a close tab on all Isildur's descendants, but not because of a deep compassion for poor successors of a ragged royal house. And a lot of secrecy around young and not so young dunedain, stationed at his court, was needed not for theirs protection, but for a protection of an ace hidden up in Elves' sleeve - an unconquering power, which was not obtainable by nobody, but by the heir of Isildur.
Nevertheless none of the heirs of Numenorian kings brought up sheltered in Rivendell. If Aragorn by the young age of 20 has already returned to Rivendell from having done “a great deeds”, which is, considering the situation in Eriador, could be no other than a big fights with enemies, then it save to assume that other his 15 predecessors were no less as brave and active participants in dangerous battles, as he was. You can't call it being sheltered and protected.
So the heirs of Isildur lived all their lives and died as plain Rangers, because it was not politically beneficial for the Elves. And I see no reason for the Elves to make an exception to Aragorn, and I suspect there was none. He was treated like all others Isildur’s heirs.