Attack the same way by launching longs balls into the opposing teams 1st attacking third with one of the midfielders to chase it down. When that Midfielder gets tired use another.  No need to try to score for another goal but if it happens go 1 vs. 1 or 1 vs. 2 or 3. Waste time.

Winning a match like this bring up FIFA rankings regardless if it was the reserve players in Argentina. Even a tie might have helped. Playing the match to win involved tactics. The game does not always have to look like a beautiful game.

2) Go for a tie with no new subs unless either a forward or midfielder is exhausted. If so give instructions to make sure your reserve player (a seasoned player with pace) can do #1 above.

3)  No need too.

4) Very much so. All are on a plan even though the game changes during match time.

I would have done #1 as soon as Jamaica scored. They could have won the game. Of course this must be practiced in training sessions and practice matches with opposition. That may not have happened, but knowing who you opponent was it may have certainly produced another result and one many would have certainly enjoy and these questions probably never been asked.

These types of things often happen for young talented coaches being tested at the international level. He just needs some more mature guidance and better assistance with the tactical preparation in training sessions
from an outsider that can help change direction for one match and the other that will follow.