Slitherine

If given the choice, say when raising a new army in the Imjin Campaign or in non potluck multiplayer, why would I ever take Korean Bubyeong (Medium Foot with Heavy Weapons) versus GunByeongs (Korean Mixed Infantry of Medium foot with 50% Bow and 50% heavy weapons)? This is because, according to the manual and what I've seen in game, Gunbyeongs fight as 100% heavy weapons in melee as the polearm infantry are assumed to form the front ranks.

Pure bubyeongs don't seem to have a niche, since Gunbyeongs fight just as well and also can shoot. As Ming, I will grab bubing units (or their punchier Kuijia Bubing) because Ming does not have a hard point to use as a counterattack against infantry otherwise. But I have a hard time justifying their existence in the Korean army, since Gunbyeong and Bubyeong seem to cost the same too!

I thought it may be that pure melee infantry can charge cavalry, but realize that that is not quite true in Sengoku Jidai, since only Warriors or determined foot can charge horses (wait does that mean Yumi Samurai can charge cav?), and Bubyeongs are medium foot. (Are there even a heavy infantry unit anywhere here? I think Hatamoto Samurai are determined foot, but I don't think heavy foot exists).

I do get the historical purpose, and commanders usually do not get to choose their forces, so they do have their place. I do have a hard time justifying picking them if I get the chance, since Gunbyeongs are so good (especially when hiding in the forest versus spears). Any thoughts on how one should use the unloved Bubyeong's they get?

They are slightly better in melee than the mixed units because (not entirely logically given the rationale you mention) they cancel 100% of the enemy armour advantage, whereas the mixed unit only cancels half of it.

I usually use them in woods.

Thanks Richard for the note. As you mentioned, it is not entirely logical, but cancelling out the full armour bonus makes them have a niche if some stray Hatamoto samurai strays into the woods. Good to know!