Jose Altuve, Alex Bregman and Yordan Alvarez should bat 1-2-3.
Altuve, Bregman and Alvarez are a lethal combination at the top of the order. Jose Altuve is a nightmare leadoff hitter for opposing pitchers to navigate. He's a free-swinger that bashes first pitch fastballs over the fence with ease. If a pitcher tries to ease himself into the game, Altuve will ensure the Astros have a 1-0 lead.
His aggressive nature does lend to some quick outs, so Alex Bregman is a perfect #2 hitter to follow him. Bregman is incredibly patient and sees a ton of pitches. His propensity to work walks helps drive up an opposing starter's pitch count early. On the year, Bregman is hitting .253 with a .356 OBP and .775 OPS when batting second.
And Yordan Alvarez has to bat third. At his worst, Yordan is one of the four best hitters on planet earth, in a league only rivaled by Judge, Ohtani, and this year, Acuña. At his best, there's not another hitter better.
So why has he been batting fifth? He simply can't miss out on any more at-bats with games hanging in the balance. In the Astros 3-1 loss to New York on Saturday, the game ended with Alvarez on deck. He's one of the best batters on the planet and finished the day with three total plate appearances. That simply can't continue. Write Yordan's name third in the order whether he is in left field or at DH and don't even think about moving it.