Aragorn can heal (because he is a king) but he can't speak to animals, speak to plants, or survive extreme temperatures.
Dar can speak to animals but he can't speak to plants or survive extreme temperatures.
In order to "have something in common" it requires more than one instance...
Who TF is Rexxar?!
There are more that one instance of nature heroes talking to animals and plants and healing.
And it makes sense as rangers fought alone and didn't have clerics to patch them up or druids to talk for them. Especially in older editions where natural healing was slow and wilderness allies were limited.