Not sure the question about "stronger" can be answered. Weedmaster is a mix of 2,4-D and dicamba. Grazon next is mix of 2,4-D and Aminopyralid. They are different chemicals with a different list of weeds they will kill/control. Some overlap on the list of weeds, but some different. One may be "stronger" on some weeds and the other "stronger" on other weeds. Really can't say that one is stronger than the other. Grazon next has a fairly long residual (kills some germinating seed weeks/months after application). Both have 2,4-D which I think requires a license to purchase/apply in Texas (no license required here). Some crops will be very susceptible to drift from the dicamba in weedmaster (2,4-d as well), but some of that risk has been eliminated with GMO herbicide ready crops in some soybean and cotton varieties.
Applying herbicides late (June) seems to cause more burning of desirable grasses. Also when it is very hot. Also in drought, which may also make it less effective on weed control. Overlapping will double the rate and may cause burning as well. Tank mix with remedy will burn bermuda as well. Neither will "kill" bermuda, but may burn it badly. Very hard to really "kill" bermuda. People wanting to get rid of bermuda wish that were the case, but bermuda will come back from a single application of most herbicides.
Point is to review the label for weeds controlled, application rate, gallons of water per acre, time of year and other condition issues. My opinion is that Grazon Next will be "stronger" on most weeds (but not all) and Weedmaster will be "stronger" on some weeds (dog fennel) and stronger on hurting your neighbor's cotton and soybeans depending on variety.
