We only had two left from the six that we bought in 2020 (not very good going as they started off so well

We had hoped to find new homes for these two, but weren't prepared for them to go somewhere shady so we ended up keeping them.
One has looked a mess for months now. She has been pecked, lost a lot of feathers and doesn't lay eggs. The other lays an egg every day, but can be nasty. She pecked the other hens (sometimes badly), presumably because she sensed that they were sick, and they were isolated, but died. We thought these two were getting on ok as the pecked one began to re-grow her feathers.....
The new hens are in the big coop with access to the covered run, but "the two" were relocated to a new, smaller coop with an upstairs and downstairs. They were put in the chicken tractor during the day. However, I think that the heat, and change of circumstances stressed them and caused the bully to peck at the other one.
Any ideas on how to introduce them or whether I should?
Linda