Some kind of Ro-Go improvement.
Ro-Go experimental at 1.7 → O-I at least 6.0 BR that’s quite a jump BR.
While the rest like Type 4 is out of the question.
I’m not against proto/blueprint tanks for Japanese since they are desperately need as their native vehicles, but heavy tanks isn’t needed.
I mean there is the Type 4 O-Ro and Type 5 O-Ro Kai but the sources on that things existence is rough at best and completely fake at worst. The only actual information is post-soviet collapse archive information from WW2 that people refer to but I can’t even find the original source but apparently it existed.
That source is erroneous, the elongated +5" motor (& Small GCS, needed to maintain the Center of Gravity) were only introduced with the Lot 12 (-120C-5) production run.
The difference between the AIM-120A and -120B is that the latter uses an Electronically Reprogrammable GCS section, so doesn’t need to undergo a deep maintenance cycle to update the Software that it runs. And as such there are later revisions of the -120A that are equivalent to the -120B at various stages.
The main change was the introduction of Clipped wings & fins for internal carriage on the F-22.
The only different they could add to the AIM-120B in game is improved ECM and better tracking rates due to later software upgrades but that’s about it.
Equipment with such as AN/APG-73 RUG I radar, AN/AAS-38B pod, IR AIM-9L & AIM-9M-8, SARH AIM-7P Blk II, AIM-120 AMRAAM (AIM-120B/AIM-120C-4/AIM-120C-5), AGM-65E & AGM-65F Maverick and AGM-154A JSOW. My guess
USMC F/A-18C+ or F/A-18C late (AN/APG-73 RUG II or AN/APG-79(V)4 AESA) ?