Wither .json file contains not enough information

In the wither’s .json file, the attacks of the wither are not shown. This includes but is not limited to: the skull firing information, how fast it fires (it fires faster when lower on health), how many skulls in a burst, the delay between bursts, the explosion strength at spawning in, the number of wither skeletons it creates, the strength of the explosions it creates at half health, how far and often the wither charges, how much damage it deals, the area which it destroys blocks around itself and the strength of the explosion when it dies.