All of "Oread" is written as a command, which is a strange and unexpected way to write a poem. Who wants to feel like they're being told what to do while reading a poem? Luckily, we never feel under attack when reading "Oread," because the nymph is too busy bossing the sea to bother with us. And us? We're just marveling at Oread's skill with words. She's commanding the sea to whirl up and meet the land, and whether or not this actually happens, she's making it happen in words—her awesome images are created out of nothing but language. Words are more powerful than either the land or the sea in "Oread." And that's what makes our Oread such a butt-kicking nymph.
"Oread" isn't about the land or the sea at all. It's all about language.
"Oread" is about our place in the natural world. You're reading way too much into it if you think that the whole poem is a way of expressing the power of words.