For the sake of argument, lets say shodai Godzilla in the Heisei timeline has a similar structure and powers as Heisei. I believe his recovering would have stunted his growth, plus if he's hibernating in Tokyo bay, than there would not be any radiation supplies until the storm in 84. According to this site
http://www.rickcampbellauthor.com/style ... tml#topic3, nuclear submarines usually can have up to 8 nuclear warheads. Unless it was stated in King ghidorah the number, lets say it had 8 warheads that Heisei Godzilla feed on. And lets say it took half of them to cure him of the bacteria. That means at 4 warheads making Heisei grow 20 meters, 1 warhead gives him 5 meters of growth.
Here is my guess. Heisei's traveling through Tokyo bay wakes Shodai but Shodai seeing the much bigger Godzilla does not decide to engage him but instead observes. The russian and Us missles hit one another. Shodai absorbs half and grows 5 meters or so. Hearing the bird chirping sound, he follows behind Heisei watches from a distance. After Heisei goes into the volcano, Shodai swims back to tokyo and does his own rampage looking around, and then leaves. The world is on watch as they now a smaller Godzilla is on the loose. But with his wondering around, there are even more Godzilla cells, prompting the governments to develop the ANEB even faster and with more corporation as the world has a common foe. Also nuclear subs are decommissioned out of the pacific. The Super x 2 is also built faster to combat the Shodai Godzilla. Biollante mostly happens the same but Shodai gets to rose biollante first as since G-cells are eaiser to obtain, biomajor and saradia have less incentive to release Heisei Godzilla. Also, I think Shodai would have gotten hold of one more nuclear sub before they all got completely decommissioned so I feel he would be about 65 to 70 meters by Biollante. Since Shodai breath is more of a flame thrower, the fire mirror would not I believe reflect as successfully as Heisei's beam. But by the same token, it not be as damaged since it's not as focused on one spot, so the fire mirror is more like a shield instead of a counter weapon. So it takes longer for Shodai to damage it and it uses more of his energy. When he fights Rose Biollante, it's more or less a stalemate since he does not have much energy to use his breath and he gets out of biollante tendrils and leaves after awhile. During this time, Heisei escapes a month after Shodai and Rose Bios fight (the volcano was active and unstable anways so it was a matter of time) curious as he senses two kaiju in the area. He remembers Biollante's call and wonders why he senses himself (Shodai is just another similar anime to himself but not himself). He goes and finishes off the recovering biollante with less energy wasted. At the same time, Shodai encounters Miki and Miki has more success diverting him since he is not as big and is low on energy.
That's all I have right now.
GVK: TNE is a modern day 70s Showa Godzilla movie. Being a massive budget modern blockbuster CGI film instead of traditional 70s tokusatsu techniques doesn't change that.
Monsterverse is not similar to either MCU nor Bayformers just because all three are big budget CGI blockbuster franchises.
