He doesn't need more out and about socialization, he needs to be better socialized within your home with a variety of people. Or, maybe he needs a good correction when he does this with your daughters. I don't know, I haven't seen your puppy in action. But, some dogs that go through a rather stupid period, can be a whole lot better once they mature.
Or they can just be a lot bigger and more intimidating.
Jenna, RN CGC & Babs, CD RA CGC HIC
Heidi, RA CGC
SG3 Odessa, SchH1, Kkl1, AD
Ninja, RN CGC & Milla, RN CGC
Joy, Star Puppy, RN CGC
Dolly CGC & Bear CGC