“Corner infielder” seems generous. Murakami is probably more like a first baseman by process of elimination until he can’t hack even that anymore, which shouldn’t be long now.
But you might be right in that he’s taking the shorter deal to try to fix his swing and miss issues here, and doing so with a team where there’s almost no pressure to make the playoffs—so he can focus on himself versus on the team—and all while making more money than he ever could at home seems like a winning strategy. If he successfully fixes his issue, he might get way, way into nine figures starting 2028. And if he doesn’t? Well, then, worst case, he can always go back home with money-for-life and rake for another ten years in an only-slightly inferior league that speaks his native language. Seems like a smart plan to me.