I'm one of those people who root for the underdog...so I don't have any particularly meek girls (I would have to keep them in the house. Lol)
I have, in one coop langshan (big, hardy, and great with their own and other hens' chicks), orpingtons (dito), wyandottes (bossy but not bullies ), Easter Eggers (friendly but flighty), and one barred rock (most aggressive), and a cuckoo marans (gentle and friendly), a couple of mixed hens (CLB mix) with top notches (no pecking that I've seen)
The other coop has much the same except with a RIR instead of a barred rock. My RIR isn't gentle but she isn't a bully like my barred rock. I would Never have a barred rock without a rooster to keep her in line. Fortunately my rooster is very chick friendly and makes sure they get food, water, and treats. He keeps Rocky in line.
Disclaimer

; my barred rock may be slightly aggressive but others have very good personalities, so I've heard.
I had a Sussex who was so mean that I had to give her away. I hated her and Visa versa but she was great at her new home.
I wouldn't add meek breeds or bantams unless I added a group all at once and raised them with a broody. (I am thinking of adding dorkings or favorelle next spring when my hens go broody.
Conclusion: chickens have individual personalities and you never know until you try.