I see what you're saying, and I agree in most cases. However, Bella Ramsey (and Isabela Merced too) being so small constantly takes me out of things.
The show itself kind of does an own goal on this topic. In the first episode, Jesse tells Ellie that he told the big dude she was play fighting with to pop his shoulder or else he would've knocked Ellie out (which is true to real life). That guy is way bigger than Ellie, and if he wasn't holding back, he would've given her a concussion (maybe even shattered some bones in her face).
So based on the show's own logic, Ellie & Dina taking on the WLF (even if they are only targeting a small faction) isn't really believable... but whatever. It is what it is. I will still watch and generally enjoy the show