Sounds like they were very ad-hoc for the most part, with exact equipment and tactics depending very much on the local conditions and leadership.
A small band out in the middle of nowhere, led by a monk may have had no more than a few old guns or farm tools, a handful of red kerchiefs, and depended more heavily on crazy mysticism and countryside traditions. But a band out in say, the northeast harassing the Japanese might have crude uniforms with red caps or armbands, a mix of old local arms/warlord surplus/stolen Japanese rifles, and a nominally capable local as a leader.
Either way, they'd have some kind of red marker (not a star - too early for that), and would would heavily depend on their knowledge of the local area to have any kind of effectiveness.
I'd make a mix of figures (some with crude or worn uniforms and some with peasant wear) and a mix of weapons (it's up to you as to how many should actually have guns). You could maybe paint up a monk or two and a couple of better looking chaps, then rotate figures as "leader" and "lieutenants" depending on how crazy you want the band to be. If it's time for a Simba-esque charge - let a monk (or a horrible looking peasant) lead. If you need them to behave sensibly, maybe the fellow with a good rifle and something approximating a real uniform can be in charge. Either way, it's easy to change the character of a band when all the figures are individuals.