Joshua beat him using proven tactics.
For round 3:
Ruiz now needs to train to twist, use more upper body movement, to break out of a clinch, to box at more varied angles, to time and limit his flurries - very them more, to box low.
That will be difficult with the weight he is carrying and it's a lot to take on board.
If he does the above he can beat AJ in fight III
. If not then as long as AJ doesn't break from the tactics he employed in fight II and doesn't leave an opening AJ will win. AJ let him Ruiz in 2 or 3 times in fight II. AJ needs to learn not to trade with Ruiz at the middle-distance.
Saying all of that AJ and Wilder are both limited fighters compared to Fury and they only have a punchers chance against him. In Wilder's case that is a hell of a punch though