You can pluck arms, armor, and the methods to make and use them from any point in history, and multiple points at that. Your goal is to field an army of foot soldiers from any pre-firearm point in history. We’ll use the mid 15th century as a cutoff, as that marked the introduction of matchlocks to Europe.
So you could outfit Hoplites with katanas, Roman shields, and gothic cuirasses if you’d like. Pretty much anything goes. So what’s the best-equipped group of foot soldiers you could patch together?