Oneo f the big reasons the Heat largely overachieved last year and aren't the same this year is because their role playing shooters, who had career years last year in Vincent and Strus, can't make a shot this year.
That's kinda what can happen from year to year now. Way more variance for teams that don't have a top 5 player. You can be a contender one year based on guys hitting open 3s and the next year you're just a run of the mill playoff team because those same guys percentages drop 5 and 6 points.