I pulled the stats from the same website
Ozil has played precisely 4487 mins has racked up 19 assists.
Santi has played 6195 mins in the same period has has racked up 21 assists.
Even if you include Santi's first season which is what I assume they did, then it's 9496 mins and 34 assists, which is an assist every 279 mins vs Ozil's assist every 236. Whatever way you spin it, Santi hasn't proven to be any more creative, even using the Premier League's measure.