Uh... I don't know how much you know about MLP but Bearer of an Element of Harmony is not exactly a position. You are right that the Elements are Virtues but they are not only Virtues.
Twilight, Pinkie Pie, Rainbow Dash, Rarity, Applejack and Fluttershy don't merely use the Elements, they ARE the Elements. The objects we see are Harmonious Artifacts that do the job for now but it is entirely possible for whatever the Elements(objects) do be done by the Elements(individuals) when Harmony is stronger/more present in the World.
The only thing close to alternate candidates is the Young Six, but only one of them is a pony, another is a Changeling(with everything that happened I hope Ocellus is still alive) and the rest are creatures that have not been... friendly with/known by Equestria so that is another issue.
We should just focus on the ones we have instead of getting new ones.
While the elements of harmony (the items) themselves are implied to be more or less useless without the bearers, we don't exactly see the bearers showing element-related powers THAT often...
Closest I can think of is the "Rainbow Power" they use against Tirek, but even there they only use it the once, and after opening the chest the Tree of Harmony gave them after they returned the elements to the tree.
If I remember right they sort of use that power again in the last season against Sombra after he destroys the elements, but that's in season 9, basically with Harmony at its strongest, and it's the FIRST time they do it without being...
well, HELPED, by the elements, or the tree.
Comics have it happen in a few other cases, but comics are not canon...
Sunset used Element of Magic. It gave her demonic form, but it may be entirely due to her mentality and it still shows that sufficiently skilled mage can squeeze a considerable amount of magic power from the trinket. If anything, Twilight situation is a potential reason to study elements more closely.
eh, the Element of Magic is still a powerful magical artifact.
Problem is,
it's supposed to only be used by Twilight. Or, I suppose, another worthy bearer, but we're never shown anyone else, unless you count the Alicorn Sisters in the distant path.
to be fair we also don't know what the deal with Sunset and the Human world is here. For all we know there isn't one.
Who knows... maybe we'll get to check the elements of harmony one die. I'd be curious to see what our lantern touch can get from them. Or if they can be researched by us at all.
I wonder if Twilight has any faith in Celestia still. We told her to keep that faith, but it ultimately got Spike killed. And while Luna was revealed to be an impostor, I don't know if she ever learned that the Celestia who tore her down was also a fake. She might've learned it if she tried to send more letters to Celestia after the incident, but any number of things could've gotten in the way. Trauma and the fact that Spike normally sent those letters, Celestia intentionally secluding herself due to the Dawnbreaker business...
Where are the other Elements in this? I get that we came in around season 1 of MLP so their bonds are not very strong in the face of all this eldritch bullshit, but I'm trying to piece together whether the others tried to help Twilight but got rebuffed or if they got caught up in their own issues (or being part of our cult) and were unable to reach out to their friend rotting away in her treehouse.
I remember Bird once saying that "to them, the experience feels a bit like a dream when they think of it".
Generally speaking, they're not THAT close. Keep in mind that after Nightmare Moon
they never had any follow up adventure, or very few at the most.
We never even reached
halfway through season 1 before things started going bad for Twilight.
So... they had a bonding moment, they had a few friendly encounters and events for a couple months, then Twilight got depressed and basically shut them down.
