This method works for any race/class. As long as your Tav has 17 Str, and Athletics Proficiency, this will work. You also want at least one of your characters to act after the Mind Flayer in initiative order so they can shove the Mind Flayer and force Zhalk to move, provoking at least one attack of opportunity. You can basically get a free attack on him every round. Also, yeeting the Lesser Imp on to the higher level is a new tactic that basically ensures that it will remain alive, and keep the Mind Flayer friendly until the end of the fight.
One last note, if you kill the wandering brain, and then go back and recruit Us, you get an extra 10 xp. If you try to kill the wandering brain with Us in your party, Us goes hostile.