This is an old quote of Nandan from late 206 WRC times (I read it in Czech so please pardon my translation into English):

The drivers are those who confirm the correct choice of changes not those who select them. You can see the result yourself. With that I don't want to say that the driver is not important for the development. It's always great to have a good driver who goes always flat out and mainly all the time with same style.
I think that many of us remember what followed shortly after this - the 307 WRC disaster. For sure Nandan brought many revolutionary technical solutions into the world of rally such as the 206 WRC with longitudinal gearbox mounted on the transversal engine but I myslef as an engineer (in different field) feel that we tend to think that we know best and in a sport which is mainly about driver's confidence there shall be someone keeping the engineer's minds on reasonable level so that the drivers stay first. Let's remmember that another engineer Willy Rampf from VW always told in his interview that the first and foremost was how the drivers felt the car.