Hi Joey,
I've never been a huge fan of subohm tanks personally. However a few months ago I bought the Kanger subtank mini just because people were raving about them. I found the vertical OCC 0.5 ohm worked great, albeit expensive. Not to mention I had to fire them at about 40 watts to get any flavor. Big drain on my batteries.
But part of the advantage of using an RTA is cost. A little wire and some organic cotton for a few bucks and you're set for a year technically. Anyway, the Kanger subtank comes with an RBA head meant for horizontal builds. It just wasn't working for me. Either constant flooding or dry hits. Mind you I use heavy VG (80/20) liquids. But what I discovered was that people were doing vertical builds in the RBA deck and everything turned around for me. Fabulous flavor and dense vapor at reasonably low wattage.
So my point finally
I'm sure your Herakles will work just fine with the standard pre-built coils. However if you get an RBA with it, forget building them horizontally. Vertical coils are the way to go with subtanks. Hope this makes some sense.