So let me start with .. I don't want my statement of Aurier being good to be mistaken for me saying Trippier is brick.
To me a big part of Aurier's advantage (somewhat like Walker) is simply who would you prefer to play against, Pace, Physicality and the ability to beat their man generally means most teams would prefer to face Trippier vs either of Walker/Aurier. The fact that in the past we have seen people target Trippier (and Davies), which I don't recall seeing against Rose/Walker only highlights that.
I think Trippier is already 2nd choice (so Poch's view), hopefully he steps up and brings his form/tactics of last season (especially against team that park the bus), which quite honestly is as simple as play off Eriksen to buy space and whoever gets that space put an early cross in. With Dele, Harry and potentially Llorente, lots of opportunity.