So I just notice that in my 2nd playthrough there's 2 route to save the slave that prince from Dorgania interest in, talk to the prince or talk to Brad friends

Is talking to Brad friends a better choice? Since you skip saving the pregnant slave quest if you just talk with the prince or there will be another quest for that?

Well, whatever you do, don't free them. I've basically thrown them out of my playthrough trying to be a good guy.