I know many people do not want to hear this but if you absolutely can not separate the aggressive birds into a different rooms then rehoming them may be your best course of action, not only for the safety issue but all the well being of your other birds.
I was faced with this, being a newbie as well and getting Parrotlets hoping to keep them in the same room as the other birds. I added birds fast and ran into some of the same problems. Turns out no matter how good they are with other birds when babies as they mature they become very aggressive. They not only went into attack mode whenever out or when bird came near their cage but they yelled at the other birds all the time too. My GCC was plucking or barbering her feathers and I finally realized it may be stress due to the P'lets. After months I decided to rehome them and now L. Angels chest feathers are beautiful and she seems less stressed.
Let me also say I have found that there is a big difference between birds that just don't like each other and aggressive birds. My Linnie HATES my Green Cheek but does not attack for no reason or seek her out to attack like the P'lets did. They can be out at the same time with supervision and when they get testy with each other we do a time out for one or both birds. But neither is over stressed with situation based on my observations.
My point is no matter how many different out of cage times you have or how far you separate them in the same room the aggressive birds will still stress out the others causing additional problems with the rest of the flock.
Sometimes rehoming is necessary for the safety and well being of all the birds including the ones you keep with you. It should not be looked down upon and should be considered the right thing to do in certain situations.
Of course I am no where as experienced as the other posters on here, but that is just my 2 cents
I really hope you can figure this out and I feel your pain
I was faced with this, being a newbie as well and getting Parrotlets hoping to keep them in the same room as the other birds. I added birds fast and ran into some of the same problems. Turns out no matter how good they are with other birds when babies as they mature they become very aggressive. They not only went into attack mode whenever out or when bird came near their cage but they yelled at the other birds all the time too. My GCC was plucking or barbering her feathers and I finally realized it may be stress due to the P'lets. After months I decided to rehome them and now L. Angels chest feathers are beautiful and she seems less stressed.
Let me also say I have found that there is a big difference between birds that just don't like each other and aggressive birds. My Linnie HATES my Green Cheek but does not attack for no reason or seek her out to attack like the P'lets did. They can be out at the same time with supervision and when they get testy with each other we do a time out for one or both birds. But neither is over stressed with situation based on my observations.
My point is no matter how many different out of cage times you have or how far you separate them in the same room the aggressive birds will still stress out the others causing additional problems with the rest of the flock.
Sometimes rehoming is necessary for the safety and well being of all the birds including the ones you keep with you. It should not be looked down upon and should be considered the right thing to do in certain situations.
Of course I am no where as experienced as the other posters on here, but that is just my 2 cents
I really hope you can figure this out and I feel your pain