Fuck it, they should add Sony and Hitachi and manufacture everything. Mitsubishi is already heavily in the power generation game (on a scale that most people won't recognize along with Hitachi - it is huge). Japan is very corpo focused. If they added just a measly two more corporations, they could easily take over global production. I'm not even kidding here. Both Hitachi and Mitsubishi have a huge amount of global control over the power generation market.
How do I know this? I'm contracted to both. Every single order is specifically related to nuclear power generation. I make critical replacement parts that fit in the turbines of nuclear generators. I'm technically under NDA, but fuck it. These parts made from G-10 or G-11 fiberglass, and their tolerances are shit. Oh man, don't get me even close to started on why I won't approach a device made my Siemens Medical.
I'm amazed how much stuff is apparently made by Panasonic. I'm fairly sure I had to install some Panasonic automatic door sensors at one point.
Japan and South Korea could probably take over the entire global manufacturing industry and no one would notice since they basically make everything already anyway.
Tbh that's the 80s and why these companies all exist today, Japanese economy was kinda peerless at the time.
You're also forgetting the likes of Toshiba, Toyota & Fujitsu, who are also still very dominant in their respective areas.
Fujitsu is the one least attached to the consumer market, but what people don't realise is a surprisingly large number of government supercomputer systems across the world run on Fujitsu systems. They don't really have any competitors in that space any more.
I didn't really forget them; I just have no personal experience with those companies. I can personally attest to the power gen from Mistubishi and Hitachi being 2024 (and contracted to 2030), seeking the production of specifically nuclear power generation and the parts required for such.
You are entirely correct, though. If Japan really wanted to they could, in fact, take over many major fabrication sectors up to and including the aforementioned car market. China is now, imo, the bottleneck for most countries.