I guess theoretically if you target the escorts now, there’s fewer in the future making it easier to get at the convoys more easily and safely?That strategy is flawed actually. Sinking the escorts, unless you get most or all of them, leaves the convoy intact. It is the merchant ships and their cargo in a guerre de course that are the important target. Better a U-boat sinks one or two merchants and spends time evading the escort's retaliation, than sinking an escort and facing that same retaliation having accomplished next to nothing for it.