Brisket and Chicken for 200

You are solid in the range of the packers, my estimate is that you need 130 pounds raw to start, ending with about 1/3 pound brisket per person. In terms of the chicken, assuming 8 pieces yield per chicken, you end up with 80 pieces from 10 chickens. That seems a little light.

Landarc is correct and you should have someone regulation brisket until everyone has gotten some. I do a fundraiser every spring and we go through a lb of raw brisket per person but people paid $45 a ticket so they are trying to get their monies worth I guess. 130-150lbs raw brisket and 20-25 birds

We did a wedding a few weeks ago with the same items & numbers as you. I did 14 packers & 150 leg/thigh combinations along with sides. Some of the packers were a little smaller, as I bought in cases and didnt have control as to the sizes. After service, we had 2 full briskets & several pieces of chicken left over. Not really all that bad, my biggest fear is to run out of food. I did have to start the briskets early & cook most of the night (Lang 60) then did the chicken at the event.
One thing I did do, and was surprised by it, To save some time I chopped some of the points and was slicing the flats. The chopped was more popular than the slices. Its now something that I will do more often.

I think you're on the right track. I cooked brisket and chicken (however this was pulled/shredded) for a wedding of about 110-120, but planned on 150 servings total.

I cooked 4 16# briskets and 30# bl/sl thighs and breasts (20#thighs, 10#breasts). This equaled twelve FULL half pans total and had less than one half pan of each left over. I did pulled chicken (approved by couple) as it was only myself cooking without help and presentation of cut whole chicken is not my strong suit. Chicken was smoked until ~130* and then braised in a chicken stock/butter mix until finished, drained of most of the liquid then pulled and mixed.

Good luck.