They can be as bad, or they can be genuinely good people.

Wikipedia

Flying monkeys can be anyone who believes the narcissist's fake persona including the narcissist's spouse, child, friend, sister, brother or cousin.[7]

According to Atkinson, flying monkeys are usually unwittingly manipulated people who believe the smears about the victim although they may be another narcissist working in tandem.[2]

According to Vaknin, proxy abusers can be:[4]

• the abuser's associates
• the victim's associates – manipulated to side with the abuser.
• authority and institutional figures – manipulated to side with the abuser.