I'm not making any complaint with the signing, I think he's a good player and I think it's a sound singing for us.
But he's absolutely not an upgrade on Aurier which is the point being made (I don't have a massive issue with Aurier, he's not top draw but neither is Doherty). Aurier is by quite some distance the better of the two defensively and by a small margin, Doherty is better in attacking phases. Whilst the comparisons are valid in that they both play WB (rather than FB), which is helpful whilst comparing them, how they are used in their teams is different with Doherty regularly coming off his wing to run in behind defences, whereas we opt to have Aurier stay out wide, because of this their stats will no doubt be skewed somewhat.
If we keep Aurier then our business is great. If we sell Aurier and don't by another RB/WB then I don't think our business is all that astute given Doherty's age and Tanganaga, Foyth, Toby, Sanchez, Sissoko, Gedson aren't very good options to provide cover/competition (we could go 3ATB and push Davies/Sess up as WB on the left I suppose.) But Jose has been trying out Gedson as RB in our preseason friendlies so I have major concerns that if we sell Aurier we are in exactly in the same position as we have been with Aurier, stuck with a RWB who's OK but not top draw.