A walk through drill is taught to step style pitchers
If you are saying walk throughs are not or should not be used by leap and drag pitchers I say you are wrong.
This girl is rushing through her run through, rushing leads to bad mechanics. Master walk throughs then move on to run throughs to help build explosiveness.
Slower = Smoother, Smoother = better mechanics, better mechanics leads to better form, better form leads to becoming a better pitcher.
Your all out combat style mentality doesnt fit all cases.