I always had an easy time beating 5*,6* and sometimes 7* HT with TIE Silencer. First it needs to attack at least 2 target locked ship/get attacked 2 times, then if you use the Chimaera or Executrix give some offense up, then make sure to hit HT while it's at <50% TM to get advantage, bam he's gone. It gets better when you put the Silencer as backup with Executrix since it got permanent 25% offense and retribution for a bigger chance to gain advantage.
This may sound overly complicated, but boy this ship kills HT with 200k+ damage, minimum.
