[Radoye]

t and 4-30mm cannons (you could use me-262 A1 cannon for it)

MK108 from Me-262 would not be a good match. It has almost twice the RoF of the Japanese Type 5 cannon, but also a significantly lower muzzle velocity so the ballistics are also off. The weight of shell is about the same, the Japanese is a wee bit heavier.

In layman's terms and very simplified, the German gun fires more shells in the same amount of time but each shell is less accurate and has less power than the Japanese.

MK103 wouldn't fit either, it's too powerful, but it would still be a better match than the MK108 which is way off in every aspect.