Well, my lady friend is a developmental psychopathologist. She would say a big nope on those games. Countless studies have shown they are very bad for the developing brains of children. I'm not here to argue with anyone either, or have a debate as I'm just giving you a third person answer. She could go on and on about that stuff all day. After all, she holds 3 degrees and a graduate degree on the subject. At the very least have a long open conversation about the reality of violent games. I remember one study she told me about where they used virtual reality headsets showing people eating food. The subjects in the study felt full and some became violently ill because the brain thought it was eating. Go with knowledge instead of feelings.
Also, kids will grow out of friends as they age. It won't be a big deal to "not be cool" in the long run.