Getting Harbinger and Apocalypse to track destroyers?

I'm newish (month and a half) and am really interested in using the Harbinger and Apocalypse in small gang combat. I'm really concerned about tracking though, that seems like the big issue. Can I ask more experienced players if there are certain tracking speeds with medium/large weapons that are widely accepted as necessary for hitting destroyers? Failing that are there any piloting tips that might help? I saw Chesseur's (?) Apoc video, he just stayed at 60k and burned directly away from their blob.

Quick note, I'm asking about tracking destroyers because my first degree concern is just making them viable in small gangs. I'm sure you can (well... I'm sure about the Harby, not necessarily about the Apoc) and I'd really love to learn how. I just figured that tracking was going to be the biggest issue, but if I'm barking up the wrong tree please feel free to call me an idiot as long as you then tell me which tree I should be gunning for :P

If you're feeling especially verbose, I sort of have the same question with the Ferox and Rokh, but I'm mostly interested in the Amarr laserbricks... sorry, I just really like big ships hahaha. I didn't join Eve to fly frigates all the time (ahem Faction Warfare)

Thank you in advance! o7