I only have vanilla Shogun 2 so I can only speak for the Sengoku campaign. 3.8 was welcome, playing as the Chokosabe I was really happy to see 1-turn recruiting for Samurai Archers again, so great job on finding that fix. Only two quirky things I've noticed in about 20-25 turns, apologies if they've been noted already
1. The Bow Kabaya still plays rifle sounds when the archers shoot.
2. This could be my fault or it could be a vanilla bug, I don't know. During the deployment phase of a siege battle, with myself defending, I placed archers on the walls. During the battle, when the enemy reached the walls, I ordered the archers to leave the walls and they didn't respond to the command for a good 30 seconds. Not a huge deal, I thought. But then I ordered my Yari Samurai and Ashigaru to man the walls and they absolutely would not, no matter what I did, even when the archers were completely gone. They responded to move commands within the castle grounds itself, but would not move at all when ordered to garrison the walls. As a result the enemy samurai got a free chance to scale the walls and enter the stronghold unmolested. This was extremely frustrating.
Other than that I love it. Battles are a joy to watch, it's by far the best melee in any of your mods for any of the TW games, and I use your mods for RTW, BI, M2TW, ETW, NTW, and S2. I hope my feedback helps, keep up the good work.
EDIT: Ugghhh, you'll probably have to disregard all the above. I didn't realize until afterwards that you recalled the 3.9 beta patch, and that's what I've been using. Might have something to do with it, I don't know.