On hard to kill weeds, my preference has always been for ester. Amines have left me disappointed. The three way amine formulas that have MCPP do little for the hard to kill weeds and burn the lawn more than anything else. I did have one zoysia lawn that became severely infested with black medic once. What killed it was a home made 4 way that involved 2,4-D ester, Turflon ester, dicamba and Quicksilver. No, there is not a hole in the ground where the lawn was supposed to be.
In your case, Speedzone + the label rate of Drive sounds like a good option. My clients do not pay per round, they pay for a year divided into 12, so control failures and the need to respray is on me. So that is where the hot 4 way mix comes into play. I would also look at how your product is applied. I do not ever use the Chemlawn style nozzle for post emergent herbicides. I use air inducted fan tips on a boom. On small, oddly shaped lawns, I have a wand that will hold one tip. My usual surfactant is MSO.
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