If they pass an ordinance limiting the number of chickens you can have to 4 chickens, and you already had 10, will you be "grandfathered in" and be able to keep 10 chickens? I know a lady living in Tacoma that has 3 goats, and quite a number of chickens and they cannot touch her because she had them before any rules were inacted.
I know that is not the point altogether, because many who do not have chickens now will be affected, but it might help those who already have more than 4.
Other than that, just try to get as many people at the meeting as you can. Get some that are vocal. Write letters to the newspapers. Get someone to lobby the city council members individually. One thing I found is that by the time there is a public meeting some of the council members have already made up their minds and it is important to present new arguements in your favor.
Have they already had a "committee meeting". I don't know about your jurisdiction, but often there are one or more committee meetings before the public meeting.
I spent years as a community activist involved in one specific project. We stopped them for 13 years. Finally we lost to big money and powerful attorneys. But, we sure delayed them.
Sorry I am not closer. I will take a look at your other post and see if I have any ideas. Keep up the fight. If all the chicken lovers don't speak up they won't know you are there and passionate about your rights to own chickens.