Centipede and bahia tells me that the soil is not alkaline. There is also enough rain in the area. It also tells me that the lawn is mowed with a rotary mower. I would convert to all centipede. Metsulfuron is really good for broadleaves in centipede and bermuda. The beginning of this process would be to eliminate or suppress the bahia with selective herbicides. Mowing at the right height and not applying a bermuda favorable fertilizer program is next. The remaining bermuda and bahia may be removed with Sethoxydim. Mixed lawns are a maintenance hassle unless the grass is in a clearly defined area for a specific reason. Getting the mowing right is hard unless you are doing the mowing. Unless the client is willing to pay for killing out areas and re sodding, this will take more than one season. Really think about how this lawn has been mowed, fertilized, etc. Messes like this are no accident.
I am dealing with a centipede lawn right now that was a mix of tropical weed grasses, centipede and bermuda. How it got there was improper fertilization, lack of water, and horrible mowing. It already got treated with Celsius, Image, and Quicksilver. It has been on my centipede specific fertilizer program for the past 3 months. Current stage is removal of the bermuda with Sethoxydim. Since there is irrigation, client is willing to re seed areas that are going to be wiped out with Sethoxydim. The newly seeded areas will be treated with Tenacity.
They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety.
Benjamin Franklin 1775
Sell not virtue to purchase wealth, nor Liberty to purchase power.
Benjamin Franklin Poor Richard's Almanac1738