Birds are very intelligent creatures. Also like human children, an upbringing of low attention, fear or rough or insensitive handling can result in problems that the new owner will have to contend with and fix later on. It will not be too late. Other people like larger birds, or like the way the Vos looks or the Red Side, or Grand or whichever. What matters most is the personality of each bird.
Some macaws are pals with CAGs and some little birds boss around their larger counterparts.
Some birds are incompatible with each other and will never be friends. If you take the time to properly introduce your birds, you will increase the likelihood that they will at least tolerate each other and may even become pals. Focused is the most direct, hands-on kind such as playing with your parrot. Ambient is the bird is in his cage or on his tree, and you are nearby but doing something else. All are important to the well being of your parrots, but in different levels.