This game is quite old and this thread less active, so I don't expect to get an answer anytime soon. But let's try regardless

So I have returned to the glorious days of the original Shogun, partly for nostalgia, but mainly because I currently lack a computer that can run newer Total Wars in proper graphical settings. And boy does this game still kick. The graphics are horrendously outdated, gameplay is improved in the following games and this game has probably the shallowest strategic portion. But this is still fun, and that's what matters most.

So I witnessed the same phenomenon just as I remembered: Yari Ashigarus are pretty much useless. They are meant to be cheap and weak, true, but since Yari Samurais can be recruited from the very same building, and are much more useful while not really costing that much more and taking the same recruitment time, there is no real reason to use ashigarus other than as a bait in bridge battles. Or that very unlikely scenario where I desperately need more troops without having enough koku for better units. Ultimately in my Oda playthrough, I didn't recruit a single Yari Samurai, but rather because of trying a different style, not because of funds - Bow Samurais did the real job while peasants kept the enemy away. But I think there is an easy way to make them more useful.

I'd like to make ashigarus more useful by editing them taking only 1 turn to recruit, but I can't find a file where that can be done. I found a file called 'TroopStats' in the main folder, where the base stats for units alongside with whatnot like speed can be edited, but that is not what I seek. The real question is,

How can I edit the recruitment time of units?

I'm satisfied with that edit alone, I find there is no other need for balance. It might become a problem if AI likes goes nuts with Yari Ashigarus due to their faster recruitment, but at least I want to try. I want to make the peasants a valid option!