// Last wins implementation
public void MergeWith(PortraitData other)
{
Sprites = Sprites.Concat(other.Sprites).GroupBy(d => d.Key).ToDictionary(d => d.Key, d => d.Last().Value);
PortraitTypes = PortraitTypes.Concat(other.PortraitTypes).GroupBy(d => d.Key).ToDictionary(d => d.Key, d => d.Last().Value);
Offsets = Offsets.Concat(other.Offsets).GroupBy(d => d.Key).ToDictionary(d => d.Key, d => d.Last().Value);
}