Unlike his colleague Manzo, Rikichi is gung-ho over this whole "hiring samurai" thing, and even if they can't get any samurai, he's all for fighting it out himself. "Without the barley, we'll die anyway," he logically points out, and even though his quest to find defenders for his village is a longshot at best, he really doesn't see any choice. The fight or they die, and that's all there is to it.
This stands in stark contrast to Manzo, who's also willing to do whatever it takes to survive, but whose plan involves a lot more groveling. Rikichi's plan on the other hand, doesn't involve the mercy of others. If they're going to die, at least let them die on their feet, in a way that they can control rather than the bandits.
Of course, it's easier for him to be bold, since he's young and doesn't have children to protect like Manzo does. Even so, we can see the same motivation in both characters, and notice that their common desire for survival leads them down some very different paths.
Like Manzo, he survives at the end, leading the singing in the fields, and perhaps he even deserves that happy ending a little more than the others. He was the guy pushing them this far after all, and in some ways it might even be his story more than the samurai. We won't begrudge him a little satisfaction in backing a plan and seeing it through.