Halo 4. Question about maps?

Truth is in Forge I’ve discovered various trivia and possible mistakes within two Halo 4 Maps in particular. Most of these were intentional but leave me questioning myself on why they are present in the game. For example:

Nobody has seemed to notice and if they have they haven’t reported the immense size of the Hornet within the map. It appears to be 10x larger than the original version. When it goes flying past the building, the scale of it can clearly be seen. Why is it like this?

Though just released today, I’ve already noticed a city-wide evacuation in a city… yet flying vehicles can be seen within the high rise of the city flying around like nothing is happening when below a nuclear reactor goes critical, capable of wiping out the entire city. A monorail is also active, but I assumed it was just automatic so I didn’t bother mentioning it.

If someone can shed lights and a reasonable answer to these, it would help scratch that itch on my head. Thanks!