Sorry, but Hunters and Rangers AREN'T the same thing lorewise. That's like thinking DKs and Warriors are the same thing. Both use plate, both use swords, both can go tanky. Hunters are guardians and protectors of the lower fauna in the wilds. A Ranger is more of a military unit, trained for battle and protecting their respective livelyhood.
No one would accuse any of the Windrunner sisters of being "Hunters", because they are Rangers. Night Elf sentinels are the same thing because they are the battle ready protectors of the NElf lands. In fact the only sentinel that was shown to have a pet was Raene Wolfrunner. Another thing is that Rangers cannot track mobs like a hunter can.
Maybe with the next XPac or whenever we see the return of Alleria windrunner can Blizz introduce the Ranger class into the game. Rangers, though, I really only see lorewise as being an Elf thing only. The human Nathonos Blightcaller was trained by Sylvanis to be a Ranger, and it pretty much pissed off Lorthermar off to no ends seeing as the Ranger secrets are highly guarded by the High/Blood elves. Maybe Humans could become Rangers as well with Alleria back, which would let the Forsaken become Rangers as well and be the Dark Rangers like Sylvanis is.
Afaik, Black Arrow is a Dark Ranger ability that was copied and modified.
I'm sure there's more, this is the one I know of.
Imo, the reason they're not bothering with modifying Marks has really nothing to do with lore or hunter flavor but more to do with the fact that hunters are the most played class.... obviously we're the most happy and need the least fixes. All they try to do with class buffs and nerfs is balance the playerbase among the various classes. i.e. if your class is under-represented it will be buffed the most. This is not my perception, this is directly off GC tweets.