As mentioned in other threads, we are currently using a similar system for awarding achievements on Console as we are on Steam and Mobile. This means that to abide by the rules provided by the console manufacturers (who are a lot more strict compared to Steam or Google/Apple), a specific action must be performed to award the achievement. In the case of Troop achievements, they will unlock when you receive a new troop, but unfortunately not when you get a duplicate. These achievements will show up the next time you get a new troop (which should only affect players who already own the troop(s)). This is also the same for other achievements like leveling up, ascending a troop to Mythic and many of the other achievements.
tl;dr - You do not need to craft another version of Xathenos, just unlock a new troop.
Here is a picture below of my account being awarded the achievements!
