I don't know... the fangirl in me wants to say that
of course they could have done Godzilla, but honestly I'm not sure
I'm thinking that maybe we're just so used to seeing Godzilla in certain settings that we can't imagine it any other way, but that doesn't nescesarily mean that it wouldn't work.
There's that old Danish monster movie, Reptilicus... very weird movie, but even though it's definitely the only one of it's kind (Danish monster, sci-fi or horror movies are a rarity!), it wasn't actually as strange as I thought it would have been to see a giant reptile wrecking my own country... even though it WAS strange