that tank need to be at least able to do some kill. simply a 6.5mm or 7.62mm is useless exept against the SPAAG who have literally no armor. You need at least the 13.2mm hull gun. i did some research. there was 2 different hull MG of 13,2mm used in that tank. the first one was an Type 92 Heavy MG which was an copy Hotchkiss model 1930 AA mg. since the lack of ballistic info on the type 92 heavy MG i search the Hotchkiss which should have a very close ballistic. the Hotchkiss model 1930 AA MG had a penetration of 20mm at 400m according some source which i can't guaranty they are 100% correct.
The 2nd MG from a non totaly viable source say was apparently an type 93 Naval AA variation of the same gun. the improvement was very little from the first one. the reason of the change was apparently due to an availability. the Naval type 93 AA MG was very common on almost all Japanese ship of that time and could be use to replace the type 92 Heavy MG
take note that the that the later variation of the type 98 was fitting a type 98 20mm AA gun in the hall AND a 7mm anti aircraft MG on the top of the turret at the American style. those gun are not of any good use in the higher battle rating but at the low one with the biplane, they can show very useful to take down a plane or two.
a 4th variation of the type 92 was a prototype fitting a 37mm in the hull. with the 7mm aa gun on the top of the turret. that tank would be a nice premium.
personally i see the Type 92 as some kind of light tank destroyer because of their lack of versatility. because of the hull restriction, the tank need to face the enemy to shoot them a bit like a turretless assault tank. i would place they at the first of the destroyer line at BR.1.0 for the 13mm gun, 1.3 in stack under it for the 20mm gun. premium at BR. 1.3 for the 37mm