Wild gods are linked to the natural cycle true, but they aren't all nature wielding beings - Rezan for example uses light magic all the time. The bat loa blood and shadow, Bwonsamdi clearly wields death magic, not life/nature - and is a loa, in fact, only gonk is specifically knonw for using nature magic. Cenarius, the greatest of the wild gods, is a master of nature magic - from his father Marlone's side, but also arcane from his mother Elune's side and we know druidism is actually the balance of nature and arcane concerned with the protection of the natural life cycle - which is a comibnation of nature and arcane.
Elune uses arcane, void and light magic - never once seen her or her followers utilise life magic.
Earth Mother is Azeroth - a titan in actual fact, but the veneration of the earth is linked to the Elementals and Therazanes realm- hence the Tauren's very shamanistic origins.
An'she - is a someone we know little off - however is his power solar (nature) or Solar (arcane) or Light magic? given that the priests and paladins of An'she seem to only wielld light magic. - I would say he isa light entity and associated with the sun because he produces light?? I don't know enough about him.
Naaru are beings of light, created by Elune - so if Elune is life and that is exclusively nature magic - it makes NO SENSE, she also is the balnace between light and void. So clearly the concepts are not that clearly divisible.