The vertical parameters of the zone should be based off of proportions of the batter, per the rules. I have no idea about cricket, I know they are standing in front of sticks and a pitched ball bounces before they swing. Do they have a strike zone?
The only way I can imagine it is if there are sensors in the uniform somehow. You need a way to get strike zone changes per size of player as adjusted by batting stance. At least per the rules.
FReegards
The Wicket, which is three stumps behind the batter, there are two sticks at the top (bails), and if one of them falls, the batter is out.
Or someone in a booth adjusting the machine from batter to batter.