Is this a good idea?

I have a baby Nanday who is fearful of hands. I’ve had him a month and progress is slow. I brought my jenday into the room and introduced the two birds. I am doing training of the jenday in front of the Nanday. I’m handling the other bird and putting my open hand by the cage along with the jenday on my finger. It’s like the jenday is the reward for approaching my hand. The Nanday is very interested in the jenday. The jenday only mildly interested. I want to move the Nanday into the living room, larger cage, more activity, but he needs to be hand tame and doing step up first. Plus I want to be able to bring him back to and from the sleeping cage. It’s sad to have a hand fed baby that is afraid of hands.

A hand fed baby does not mean that he is hand tame; it just means they were fed by hand as opposed to parent fed. If the baby was not played with and frequently handled by loving , careful breeders, than for all purposes your baby is not hand anything.

But, parrots do learn from seeing other parrots do something, so your new baby will benefit from seeing you handling and playing with the jenday. Also a month is not long at all for a new parrot to settle in. Yes some do so quickly, some take weeks or months to really feel comfortable and not fearful. Go at your Nandays pace, not yours!

This is an excerpt from an article I will link in a second.
Situations like this were commonly seen with imported parrots that were not properly and gently tamed. They appear to have decided that they are only safe around their cages.

This type of behavior is also seen in domestically bred young psittacine birds that ceased to be handled before they had established strong ties to humans. This situation might occur in a pet store that has little understanding of parrots. Not comprehending just how tenuously “tame” a domestic-bred young parrot can be, the store personnel might handle baby parrots only when feeding them. If a parrot then weans prior to being sold, the store employees might cease handling the bird altogether, and the baby then is allowed to slip into a wild state. As previously mentioned, most domestically bred companion parrots are only first or second generation from the wild, so this reversion to the feral state can happen surprisingly quickly.

This fear-based behavior is also seen when parrots are confronted with something they find terrifying. This could include loud, fast-moving children or large, predatory pets.
https://petcentral.chewy.com/why-wont-my-parrot-come-out-of-the-bird-cage/

My lorikeet Lilly was “hand-raised” but once weaned was left to her own devices and reverted back to an aviary level of behaviour, so was terrified of human interaction. When I first brought her home my cockatiel Fang provided invaluable help in showing her that humans are not so scary after all, and combined with lots of food treats she became my little velcro-bird in only a few weeks.

And by the way, may I just say that “Jazzy Pizazzy” just has to be the best bird name I’ve heard in a very long time?! Well done on that one!