Do make sure you get healthy birds. It is quite common for poultry to have worms, mites/lice, and respiratory illness if you buy them from just anywhere. The worms and mites/lice are treatable but the chronic respiratory disease is a forever thing and is contagious to the other chickens. So do be careful to buy healthy ones. I prefer to buy chicks myself. But they are a lot of work to rear.
If you won't be quarantining then if they are ill the whole flock will come down with it possibly.
What I would do is to make a second coop/run and grow out some nice healthy chicks - integrate at 16 weeks of age. A growout coop is really a necessity if you plan to have chickens long term and buy chicks now and then- your layers will slow way down on their eggs as they age. So you will generally want a larger flock as they get older, or replace them.
If you get auto door openers for the two coops, life is quite nice!!
If you are simply purchasing them from the same place you bought the others, and your question is more along the lines of personality-wise how should they do, then you will be fine. Just don't buy just one hen so she won't be the only new one to reduce bullying.
