Clem is only 11 yrs old and she can hack walkers. Human body is thick, it's hard to stab the mere skin of a grown man. (though rotten flesh makes it a lot easier) and skull is...you know, that's bone, it's not easy to hack.
and Molly, she pulled Lee up with one hand, twice. Lee weighs like...around 170lbs at least? He is tall, has some muscle.
What are these girls? mutants for new era?