Basically this order is for Shields to go offline at a certain percentage and then re-activated when they’ve recharged to a certain amount.
Why this may be useful:
Having your shield go all the way down to 0 is detrimental because they don’t always come back up or don’t get the time to recharge properly under heavy fire. This allows ships captains to divide up the incoming damage between the shields and armor.
Having your shields down comes with obvious implications since you will then be vulnerable to anti-armor weapons and the underlying modules may be damaged significantly if you lower them unwisely.
I’m not sure if we’re all in agreement on this but my personal experience and some other board members suggest that either all shields or all armor is a more effective defense than a balanced mix.
The idea is not to eliminate the all shields or all armor configurations entirely but find a way to make a balanced mix more strategically significant and not less than optimal choice.