Mark-
I think maybe I'd try less lit. 1/2 a chimney may just be getting too many coals active, so you'll overshoot. Also, you might get more aggressive with shutting vents at 200 degrees. It's not uncommon for me to close 2 when I get to 195/200, and shut the other to 15-25%.
My current lighting procedure no longer uses coals in a chimney. I use a MAPP gas torch, and just light off four spots in the middle of my full ring of lump. I count about 15 seconds per spot, and that's all I need to get things going.
I've never found any benefit to running 200-225 versus running 225-250 or even up to 275. Brisket sometimes seems to do better at a lower temperature, of course, there are many here who prefer a high-heat method for that.
Having said that, there is no reason you shouldn't be able to find a lighting method that will get you in the range you are looking for, then you can figure out for yourself if that's the ideal spot for YOU to cook in.
Good luck!
R