So today I pulled a brave Hector from the banner and he did not have and + or - stats. I chose Ephraim for my free 5 star but I thought all units pulled the regular way had + or - stats. Can you pull completely neutral units?
So, if you are familiar with pokemon think of it like a nature
Timid is +spd -atk
Hardy is neutral
Quiet is +atk-spd
You roll for IVs, or Inherit values that affect buffed or nerfed stats
Tldr yes. It is just as likely as any other nature