My grey was hatched in August - if I am remembering correctly. She was fully flighted prior to being clipped, but since getting her first baby clip she has not regrown her flight feathers, so she doesn't really have control over where she "flies", if you could really call it that. She tries, and, actually, compared to most of my other clipped birds, I think she tries a lot more than most. My senegal learned very quickly that she could not really fly when she was clipped the first time, so she stopped trying. Ashlynn doesn't seem to get it. She keeps trying and crash landing wherever. She wasn't given a severe clip, so she kind of floats down, but I still worry she will hurt herself. My avian vet recommended that we NOT clip her any more severely since she is a baby, so there you have it. Is Tango clipped at all, or does he have complete flight? Is he very good at controlling where he is landing?
I have never felt comfortable with a bird the size and beak strength of a grey on my shoulder, so I have never allowed her to climb up there. Not that she doesn't try, because she still does, but I don't let her stay. She has landed on my head on occasion when trying to fly, and I simply get her down.
I do have some books I would REALLY like to recommend to you.
For the Love of Greys, by Bobbi Brinker, is specifically about greys. It also includes a couple of chapters with great input by Dr. Susan Friedman. (I may be spelling that name incorrectly because I can't find the chapters at the moment.) Dr. Friedman is the behavioralist I listen to the most. She is a psychologist (human) as well as a parrot behavioralist. If I could only afford one book, it would be this one. The book is published by Lucky Press, LLC.
Guide to Companion Parrot Behavior, by Mattie Sue Athen, and Guide to the Senegal Parrot and It's Family, by Mattie Sue Athen and Dianalee Deter. Both of these books aer published by Barron's. Barron's may have a grey specific book, but if they do I do not have it and have not read it. These are the easiest read of all the books I am recommending. Poicephalus are also from Africa, and I think everything that applies to pois applies also to greys, but that is me. I had a senegal before I had a grey, so I read that book first.
Don't Shoot the Dog!, by Karen Pryor. This book is about positive reinforcement in general and applies to all species of living creatures. It is not specifically about parrots, and there are only a few pages specifically devoted to parrots and these are interspersed throughout the book. This is probably the last one I would read, yet it will give you the most information in about training specifically. Pay close attention to the sections about domesticated animals verses non-domesticated animals, and remember that greys can in no way be considered domesticated. That requires countless generations. Karen Pryor has the most experience training marine animals, who are also non-domesticated.
Welcome to the forum and happy reading. Keep posting as much as you like.