Немогу догнать, класс UserRoles должен же быть mtm к ClientUser

Question

Немогу догнать, класс UserRoles должен же быть mtm к ClientUser

и SpecialistUser?
class PhoneModel(models.Model):
phone = models.CharField(validators=[phone_regex], max_length=13, blank=True)
is_verified = models.BooleanField(blank=False, default=False)
counter = models.IntegerField(default=0, blank=False)

def __str__(self):
return f'{self.phone}'

class UserRoles(models.Model):
is_client = models.BooleanField(default=False)
is_specialist = models.BooleanField(default=False)

class ClientUser(AbstractBaseUser):
role = models.OneToOneField(UserRoles, on_delete=models.CASCADE, primary_key=True)
phone = models.OneToOneField(PhoneModel, on_delete=models.CASCADE)

class SpecialistUser(AbstractBaseUser):
role = models.OneToOneField(UserRoles, on_delete=models.CASCADE, primary_key=True)
phone = models.OneToOneField(PhoneModel, on_delete=models.CASCADE)