bodybuilding training for hamstrings more effective than max strength speed

I think Poliquin may have used the term neurological efficiency to describe one’s ability to activate high threshold motor units and that beginners are less neurologically efficient. How does this factor in here?

Also, in studying for the NSCA exam years ago, I recall the usual gains in strength due to neural factors, not hypertrophy message. If beginners can turn on all their motor units and there’s no hypertrophy, how do they get stronger?