There are items like this in TERA for a couple reasons. Duplicate versions are sometimes created for different world regions, but still localized to English. Sometimes there are versions meant for all regions to use. Some also have lower cooldowns making them a little better. Some are tradeable and others aren't. Some are named differently because they were designed as rewards for specific events, reputation quests, Alliance, etc...

After 5+ years of TERA a lot of these items are still around even if we've switched to rewarding a single version of the item. Players hoard stuff, and there's usually no reason to punish that behavior or replace everything.