Would a USMCA/EU/JP/SK/AUS manufacturing partnership be that difficult politically? naively it seems that all parties have rough parity in standard of living, and each has leadership in a few industries and all share roughly the same environmental regulations/strategies.

The only rough patch that I could see would be in autos and aircraft which are both relatively stable industries with a history of comebacks. I would imagine that there would need to be provisions for national protection of these types of industries.