Poor Óin . . . he's really been done a nasty. This is literally his only rendition and it sucks. It feels almost as if he starts with a handicap and you need to pass the 5 dwarf restriction just to get him back to normal.
He isn't the most prominent of Thorin's company, nor an important figure in LotR, but still.
Seems like it's the trend for the dwarf archetype: mediocre unique characters.