Playing less songs per show is not at all "working smarter". I know it's exhausting playing heavy metal on stage but the amount of energy they save by playing a couple fewer songs is nothing compared to just getting from one stage to the next.
People are going to leave with a sour taste in their mouth and not want to see Megadeth the next time around. That's on top of the sub-par new material and Dave's weird semi-political ramblings working against ticket sales.
8/20 High on Fire 4free
11/16 Judas Priest