i tried this combo before, the dat was roughly 1', the gars were from 12-20" plus. for the most part, my tank was large enough to prevent any interaction between the 12"ers and the dat, but the dat would occasionally steal food from the 2' gars mouths. kinda risky, but probably no where as bad as peabass, as ime dats are pretty calm fish. if you're intent on this combo, imo it could work(i think conner has this combo now), but u'll have to watch them carefully. certain things would greatly reduce risks, ensuring they're of a compatible size(remember dats pack on a whole lot more mass in the mass to length ratio compared to gars), and that you feed carefully(perhaps let the dat get its fill before moving on to the gars) certainly would help. but as far as i've seen, dats aren't the most aggressive of fish, and problems only seem to occur when the dats steal food from the gars mouths. that's my limited experience with dats.