Well, I have some work experience with zoning laws and administrative law, and you should rely only on the wording in the code rather than what a municipal employee tells you over the phone or in writing - they are not held legally responsible if they dispense misleading or erroneous information.
I wouldnt assume that bantams are fine just because they are smaller - a chicken is a chicken, and it's really a matter of how the code defines permitted animals that matters. For example in my town, a pot bellied pig is considered a pet and chickens are livestock. Livestock is regulated much more stringently than pets. This makes no sense because it seems to me that a pig of any kind can potentially be much more destructive than a chicken, but the code is the code. Clearly a lobby of pot bellied pig fanciers managed to get that animal classified as a "pet".
Also - if you go ahead and just flout the code, and get caught, you may be ordered give up your chickens. That recently happened to someone on the board and it was a very sad situation - they had to hire an attorney, pay fines, etc.
Just my 2 cents.
Phyllis