This is my take as well. I will add that I think I'm more likely to notice an issue with the type if the type is first though since it preps me to expect a certain thing after it.

int firstName will likely trigger more alarms than firstName int but maybe thats just my perception due to familiarity. I feel like once I see the type my mind is looking to make the next part make sense whereas if I see the name first then I just assume what comes next makes sense and mentally move on.

If you think of int as an adjective, the whole situation changes. It makes sense to an English speaker, but is backwards to a Spanish speaker.