I voted HD so you can explain what that is. ...In the First World War the British took the Tribal Class destroyers Nubian and Zulu and welded them together. Once the yard was done they had a Heavy Destroyer (because the resulting ship was bigger than the originals); they named it HMS Zubian because all that had been left intact of the the two ships (due to massive mine damage on each) was the bow portion of Zulu and the aft section of Nubian. Zu + bian = Zubian. True story... Whatsa Lizardman Destroyer? Or are ya contemplating adding in one of the Stormtossed Infernal units?
I have a necron army (I know the hate so I'm keeping it small) so I'm talking necron destroyers. I had no knowledge of any others. Lizardmen destroyers sound super scary.
I voted Heavy destroyers because they are very useful at tank-busting. Are you a member of Necrontyr Online, because if so, please feel free to post it there as well - the chaps there will give you some valuable tips. If you want to sign up there too, again please feel free - I am a member of Necrontyr myself, although I am called Mithihotep the Indomitable over there.