Yeah, a large number of assets would have to be unique. JSDF does use some stuff that's already in PR - off the top of my head: M24 SWS, M18A1 Claymore, Minimi (albeit a different variant), PzF 3, Remington 870, M2HB, M167 VADS, L16 mortar, TOW, CH-47, and AH-64; SF-only M4A1, USP, and MP5A5. The UH-60JA is close except for the big
weather radar on the nose (which is why I did the UH-1H) and the F-15E could be bodged into an F-15DJ. They also used the Stinger and OH-6 until recently. But that's about it, that I can remember.
A lot of these assets do exist elsewhere, though.
CQB mod,
Lion's Roar, and
CHPower have a fair amount, of varying quality. I don't know how getting permission from these teams would go, though - CQB is long-dead and the Chinese modding community seems to interact little with the outside (BFSP, BFEditor, and such.) They also use the FH-70 howitzer (POE2 has one), the M26 hand grenade (a couple mods have this, I think; I know at least AIX does) and take delivery of Bushmaster PMVs (the also long-dead
Australian Forces mod) later this year.
Also dug up the old
faction proposal thread.