I am going by my own judgement rather than stats. Sigurdsson for me is far more creative than Ross will ever be, is much better at corners, free kicks and deliveries into the box and he was surprised me by how hard he works.
I am sure you are aware of the saying... there are lies, damn lies and statistics.
I am but I also like the phrase "a man sees what he wants to see and disregards the rest"
DCL has put up as good numbers as GS in just about every category and he is a £1m signing 20 year old from League 1 who gets dogs abuse for being "limited".
A £45m midfielder is Bernardo Silva / Leroy Sane / Raheem Sterling level. Not Gylfi.