Risacher kind of stinks or at least is not worth his salary at the moment. However at 21 years old could still grow into a playoff contributor. That is worth the gamble for Nembhart who is just too small to be a major playoff impact guy. Morez Johnson has a high floor, not sure what his ceiling is though. He may just be a bigger version of Finney-Smith which wouldn't be bad. It's hard to see him being a bust, but it is also hard to see him creating much offense. Time will tell. De Larrea and Aldama are skilled guys with length, not a bad combination to bet on. Some of the deeper roster moves like Tarik B and the Russian kid are interesting upside plays on some skilled, possibly overlooked prospects. All of these guys have good positional size. If you get 2-3 playoff worthy rotation guys out of this bunch that wouldn't be bad at all.
The ultimate question is still, how do you get a 1B tier player next to Flagg? It may have to be part of a trade in a few years once you have reclaimed some lost draft capital starting 2 drafts from now? Maybe Kyrie plays well and can be leveraged for future assets? Maybe Dirk can talk Luka into coming back and eating Texas BBQ? Maybe you get lucky with a Top 2 pick in next years draft? This doesn't have to be answered for next year's team. I would use next year to give extended playing time to that group of Risacher, Johnson, De Larrea, Aldama, etc... even at the expense of potential wins. Still, the question will need to be answered for the Mavs to be a contender again.