Neither of them replace or come “instead of” the Ki-46 or M6A.
Neither of those planes would be in the same tree position or BR as the Firefly and B-33, the purpose of which is to add Rank III+ capable strikers to Japan so players that only play thag nation can complete dailies, missions and other challenges with Srike aircraft.
They have not been added to “replace” any future Japanese aircraft.
give the cheiftain mk10 its dozer its proper engine power its thermals and make its reload 5-6s and keep it at 9.3 or move it to 8.7 with the a1a1
and the cheiftain 900 i dont see what they could do other than give it the chobham armour but it also should be downtiered considering its the same br as the Khalid