[@ERode] Yeah, I don't mind the variety of self-perceived and actual intelligence from the group. Clarity will gradually be developed along with vocabulary. Some can stay as meatheads and simpletons, but that's totally their choice. Communication between goblins, regardless of how bad their vocabulary will be, an understanding would still exist. 

I mean, I find it funny when I read on how Aya speaks, but given the complexity of what she's saying, no one gets it. Or how Saito feels like a japanese Bear Grylls but in a a small green body. Or how Hoi uses as little words as possible and gives me an image of Snorlax. 

But that's far as greenskin speak goes; learning human speech is a whole other story. Not a difficult one though.

[b]EDIT:[/b] Also, I didn't give a clear answer to your question. My bad. Would we have our adult human level intelligence, complete with an expanded vocabulary and forward-thinking mentality? Yup, we'd reach that point. It'll be up to you guys though if you wanna stick with their previous personality or have it tweaked or corrupted by life as a dirty monster.