There's no confusion there to speak of. Ballistic and energy weapons exist in the same game on the same battlemap with mostly the same range bonuses, though ballistics get a potential 10% extra from Ballistic Mastery. So, the definitions of what range a weapon is on the battlemap doesn't change based on what mount the weapon goes into.
Case and point, A plasma cannon is effectively the same range as a storm needler. That, objectively, should not mean that storm needler is one range bracket and the plasma cannon is a different range bracket. Cutoff points for when to call something short, mid or long can be subjective, though. You could argue that high tech ships are a different speed bracket than most ballistic ships that can equip larges and that can skew the result, but the apogee exists. The Sunder exists. Champion exists. The retribution exists. The prom2, surprisingly high top speed besides it’s awful maneuvering, exists.
I would use hellbore against remnant, if the build made sense. I don't use hellbore very often against remnant since the new storm needler and buffed Hephags exist, but there's two builds where I would: a BRF Hellbore Dom build and a BRF Legion build. For the Legion. 2 Hellbores, 2 heavy maulers in the rearmost composites, 1 HAC at the nose, 2 flaks, BRF small kinetics (such as, 2 light needlers 2 LACs, or 4 light needlers, or railguns or whatever). This frees up the need to use ECCM or expanded missile racks, the hellbore's flux cheapness lets you afford all these ballistics and 2 hellbores are harder to flicker than one hellbore.
Even for faster ships like fulgents and brilliants, hellbore might potentially do a bit more damage than a hephag due to getting in a cheeky final hit before they retreat away from the slow dominator or legion. You can’t always rely on the ai to use burn drive to chase, let alone it to make sense to burn drive to chsse. That's probably a really minor thing, but it's something to consider.
Radiant has 1,500 armor and 20,000 hull - that alone means hellbore has value, but hellbore is also good at stopping 1,100 12,000 hull Apex. Although the hephag is better at hitting smaller targets and isn't shield flickered as much, the Hellbore 750 HE damage per hit means its dps usually catches up to hephag thanks to armor damage calculation and minimum armor. It also costs 16 OP, that's really nice OP savings for a carrier so that it can better afford a bit more flight deck stuff.
I've been comparing hellbore and hephag interchangeably throughout this discussion, but I think I compared Hellbore more often because it is one of the most popular slots for the Dominator's larges. If the dominator could just stop wobbling so much and if it had better hardpoint weapon arcs, i'd like hephags on it more. Not that I think they're a bad choice on the dominator, I just think it skews a bit more value towards the hellbores. I think it also skews it a bit towards value for the devastator - you're more likely to be at close range where the dominators will win out over hephags, and while at 960 su range these range-buffed devastators are still worse DPS wise than the hephag they are still very versatile for a variety of reasons. Hitting frigates with dom's hardpoint hephags is kinda hard. They won't really clear fighters or many missiles. Devastators will.