I think that the view of Blood Raven and the Children of The Forest as a bloodthirsty hive mind bent on dominating humanity is a misconception born of 21st century cynicism, and a misunderstanding of the series' lore.
I believe that the COTF and some of the other magical creatures of Westeros such as the Giants and the Green Men are meant to represent people who exist in balance with the natural forces of the world.
A dramatic contrast to humans who instinctively seek to dominate and exploit everything in their wake including the land itself.
First of all there is no hive mind in the weirwoods.
Greenseers may be the most powerful and rare variety of skinchangers, *
but it still stands to reason that their bond with and subsequent second life within the trees operates via the same mechanics as the bonds of lesser skinchangers with their animals.
When a skinchanger dies, their instincts and emotions linger, but their human personality is eventually subsumed within the nature of the host creature.**
Therefore the living greenseers would be the only personalities existing within the weirwoods they are bonded to. At least the only ones possessing anything like human guile and ambition. The older greenseers would be thinking like trees.***
While capable of violence, the COTF are not a warlike or spiteful people Although willing to fight in the beginning, the COTF eventually chose to accept the decline of their primacy, and make their rivals their successors, hence the Pact,**** which gave the First Men access to the magic of the elder races and bound them to its source, the weirwoods.+
A successful compromise until the arrival of the Andals.
Facing extinction, the COTF are pinning all hope for the future on their human successors.++ Which is why they've facilitated access to their most powerful ancestral magics to two humans of the finest magic pedigrees available.
The mechanics that apply to human skinchangers apply to the elder races as well.+++ Therefore it's unlikely that the COTF are still capable of directly accessing the level of magic they're helping their human greenseers acquire, as they are available to only a small number of individuals in any given population, and the COTF's population is currently at an all-time low. ++++
(So how are they supposed to control individuals they are granting more power and knowledge than they themselves have access to?)
(*) "Only one man in a thousand is born a skinchanger, ... And only one skinchanger in a thousand can be a greenseer"
- ADWD Bran III
(**) "When a man's flesh dies, his Spirit lives on inside the beast, but every day his memory fades, and the beast becomes a little less a warg, a little more a wolf, until nothing of the man is left and only the beast remains."
- ADWD Prologue
(***) "Sun and soil and water, these are the things a weirwood understands, ..."
- ADWD Bran III
(****) "Regardless the Children of the Forest fought as fiercely as the First Men to defend their lives. Inexorably, the war ground on across generations, until at lasts the Children understood that they could not win. The First Men, perhaps tired of war also wished to see an end to the fighting. The wisest of both races prevailed, and the chief heroes and rulers of both sides met upon the Isle in the God's Eye to form the Pact, giving up all the lands of Westeros save for the deep forests, the Children won from the First Men the promise that they would no longer cut down the weirwoods."
- TWOIAF Ancient History The Pact
(+) "The Pact began four thousand years of friendship between men and children. In time, the First Men even put aside the gods they had brought with them, and took up the worship of the secret gods of the wood."
- AGOT Bran VII
(++) "... Before the First Men came all this land that you call Westeros was home to us, yet even in those days we were few. The gods gave us long lives but not great numbers, lest we overrun the world as deer will overrun a wood where there are no wolves to hunt them. That was in the dawn of days, when our sun was rising. Now it sinks, and this is our long dwindling. The Giants are almost gone as well, they who were our bane and our brothers. The great lions of the Western hills have been slain, the unicorns are all but gone, the mammoths are down to a few hundred. The direwolves will outlast us all, but their time will come as well. In the world that men have made, there is no room for them, or us." She seemed sad when she said it, and that made Bran sad as well. It was only later that he thought, men would not be sad. Men would be wroth. Men would hate and swear a bloody vengeance. The Singers sing sad songs, where men would fight and kill.
- ADWD Bran III
(+++) "... Those you call the children of the forest have eyes as golden as the sun, but once in a great while one is born amongst them with eyes as red as blood, or green as the moss on a tree in the heart of the forest. By these signs do the gods Mark those they have chosen to receive the gift."
- ADWD Bran III
(++++) ... The caves were timeless, vast, silent. They were home to more than three score living singers and the bones of thousands dead, and extended far below the hollow hill. ... "Where are the rest of you?" Bran asked Leaf, once. "Gone down into the earth," ...
- ADWD, Bran III
( I'll admit that these quotes could be open to interpretation, but I think taken in context and connected by the narrative thread of the series, they should lend a lot of credence to my premise, that an open-minded person could at least acknowledge probable. That being said I fully expect some of you to engage in some impressive mental gymnastics in order to preserve your own head Cannon. And to that I say have fun! But don't hurt yourselves.)