We have many Arcturians in the third dimension, but humanity is not aware of them as they have taken on the form of a third dimensional human. That is why there are many "channels" for our words. ALL of these channels are grounded expressions of our Arcturian Family. (For the sake of clarity, we will refer to our grounded ones as "they" when they are actually US) There are many other Arcturians in "human clothing." We think of your parable of a wolf in sheep clothing.
We hear your question, dear Jeffrees, regarding our last statement, so we shall explain, "enter into the form of Gaia as one of Her human portals.” Every person, place and thing is a component of Gaia's form. Humans, who are actually the descendants of our Galactic Federation, are to be among the most evolved physical life forms on Earth. Unfortunately, there was great devolution of humanity since the fall of Atlantis, which is why these brave Arcturians took a human form.
For many, many lifetimes, our grounded ones struggled through the challenges of life in the third dimension. They were so overwhelmed by the hardships of survival that they totally forgot their true nature. Fortunately, they had some lives in which they were able to awake enough to remember their true SELF, but often returned to forgetfulness in others’ incarnations. We remind you again that time is specific to the third and fourth dimensions. Therefore, what you perceive as many separate incarnations over many different timelines, we perceive as many expressions occurring within the NOW.
So you see, dear Jeffrees, we are everywhere, but hidden in third dimensional form, including your own cloak of humanity. Once the frequency of your world is free of the illusion of the third/forth dimensions, the costumes will fall away to reveal your true form of Light.