By complete I don't mean a set of techniques that can handle all and every situation with super human ability. But, rather all the tools needed to draw on. You don't have to go outside the art to get something. If your lacking something it isn't because Aikido doesn't have it.
Kenji Tomiki, Gozo Shioda and Minoru Mochizuki often spoke about the deficiencies within the modern Aikido movements. They stated that modern Aikido was lacking, that's one the reason we have Yoseikan, Yoshinkan and Tomiki Aikido. It's not complete. Gozo Shioda was the closest student to O'sensei, so what makes you know more than him? No martial art is complete. They all have some deficiency. Maybe you mean it's complete for you. What's complete for one is not for the other. We will all have satisfactions that are different.