Form input – Follow expected sequence or offer field validation?

Validation opposed to expectations

My team proposed to change the usual sequence of an address form. They want to put the country before the other address fields so they can validate the following fields depending on the selected country. The con is however that this deviates from the mental model of the users and it will slow down the data entry and might be slightly annoying.

Some users will enter addresses a few times a day, others not so often.

What solution is the best?