https://www.espncricinfo.com/scores/series/8368/season/2020/icc-under-19-world-cup
Australia opens its WC acct on Jan18 against the Windies.

I’ve read that batters are coached to hit the ball hard, for a T20  skill set. 

I’ve also read and heard bowlers are coached to try and bowl too much variety, again for limited overs cricket. Warne was saying bowlers need to work harder on stock balls. 

Correct KW. Now we know why players are coming thru underage cricket with a dodgy red ball batting technique. While the old fashioned accurate Glenn McGrath type bowler is a dying race.