***Warning completely untested***

Go to

Key Maps - > General -> FTL Assist Me

and click on the and ... and restore Target afterwards click box

alternatively untick everything and in the Macro Generator type in

/assist {FTL}
/stopmacro [nomod]
/targetlastenemy

This should make it so that even if your master does not have a target your slaves should still acquire one - but it may do funky things that were not intended!