I disagree.
All indigenous Japanese tanks, which are about all those from about 6.7 - 12.0, force the player into a specific playstyle. One very unique to Japan, Especially once you arrive at the autoloader stages of Japanese ground (Or you really like the ST-A3.). Japanese tanks lack armor, but rampantly make up for it in firepower and maneuverability.
For example, the Type-10.
The Type-10 has great thermals, zoom, maneverability, reload speed, a great round, but next to no armor, along with this it’s kinda gimped (to my understanding) with the turret traverse and energy bleed when turning.
You play the Type-10 by sniping (Which you can do with basically any top tier tank), flanking, or baiting shots and using your superior reload.
The T-84 and VT-4 play the opposite. Although I have not used the VT-4, I assume It’s akin to the T-90M, seeing as they’re both based off the T-72 (IIRC). Which has a basis on sniping, and using its armor to soak up shots like a sponge. It’s main weakness is the reload speed and maneuverability. The exact inverse of the Type-10
I cannot say much about the T-84, but I assume it’s akin to the BVM. Which I’ve used extensively, and most of what I’ve said about the T-90M/VT-4 (in comparison to the Type-10) stands true.
Yes, you could add these to the ground tree, and yes, they would fill the armor checkbox for Japanese tanks. But by doing so you are adding tanks to a lineup which play in the exact opposite way of every other tank in the Japanese top tier lineup.
If these were added at top tier, you would have TKX, TKX(P), Type-10, T-84, VT-4, and some CAS.
Debatably, the best part of Japanese top tier is the TKX, Type-10, and Type-90 spam lineup, having an extensive amount of tanks which play the same, and do insanely well at that playstyle calls to some players. The Oplot and VT-4 would just be weird. Yes, they’re good choices, but it just doesn’t fit into alot of what Japanese players are used to.
Japan doesn’t direly need top tier tanks, The Type-10, TKX and Type-90 lineup is absurd.
I am not against adding the VT-4 and T-84, but I just don’t see a good reason to, other than to please Thai players.