Oh, Meyer's are cute! I love their color. Remember, if you get two around the same time (like having twins), there's double the work and learning two individual personalities at the same time.
If they are juveniles and happen to both come into sexual maturity and hormonal behavior changes around the same time, you might have things a bit more hectic than if you had one. Still, it's not like you're asking about a whole flock at once.
Generally speaking, if you have a hand fed hand raised tame bird who is imprinted on humans, it will stay the same whether they have a bird friend or not. One of my Pois Griffin reverted, but it's another story, it's not because of his friendship with Raven.
Besides the Meyer's you are now thinking about, is a Pionus still the other one? Keep in mind that most Poicephalus parrots do not like other birds. The fact that Raven (Pionus) and Griffin (Ruppell's Poicephalus) are bonded, is a bit on the unusual side. The two boys are truly a couple where Raven will even feed Griffin. That's the only reason I don't worry about the size difference. Robin my other Poi (Red Bellied parrot) hates other birds as is typical of the genus. It's a pain to keep Griffin away from Robin.
