I don't think laboring under ancestral-style social assumptions necessarily implies a weak or unstable social support network, or problems maintaining social links. Particularly not the latter; if you're working with a set of unremediated instincts telling you that losing rapport with anyone in your ingroup is a disaster, then it follows that you should invest heavily in repairing any damage to it.

It does suggest some failure modes that wouldn't be present in the network of someone more willing to burn bridges, but we're talking differences in style and overall optimization, not being strictly worse at everything social.