My MUTO theory

I was thinking how Godzilla would fight the MUTOs if they were too small for him, since descriptions said that Godzilla "towered" over them. I thought maybe there would be lots of MUTOs, which was also kind of disappointing.

Then I thought: "What if ,because of their mutation, the MUTOs will grow?"

In an image from the MUTO viral campaign we see some helicopters flying over some huge holes in some mountains. We can also see Ken Watanabe's character looking at one of them in the teaser trailer. We can assume these holes are from where the MUTOs escaped.

Now, although these holes are really big, the creatures that apeared in the official trailer, like the creature who stomped its insect-like leg on the ground, are too big to have made those holes.

So my theory is that, because of the radiation they recieved or the genetic mutations they might have recieved, the MUTOs are increasing in size. Maybe they are breeding and each generation is getting bigger or each MUTO is growing eventually, kind of like Godzilla.

Maybe at the final act there is a MUTO the same size, or bigger, than Godzilla, giving him a great challenge. Maybe it even developed some special abilities.

Remember this is all speculation and that I am not saying this is what is DEFINITELY going to happen. What do you think of my theory? What is yours? Feel free to comment!