Is Saliba turning out to be Arsenal's worst ever signing?

While I have often questioned the ambition of Arsenal on the football pitch, as a business they been fantastically run. As a self-financed model, if FIFA ever wanted to be serious about Financial Fair play we would be in a strong position. This is a club who for years were able to make a profit on their best talent, only spend a fraction of the money on a replacement, and yet still find a route into the top 4.