Why should he go because of his experience? It doesn't matter if they lose these tests, surely testing out options on the tour is more important than having an experienced player there to ensure victory? Even if they were really wanting to win next month, the All Blacks have been taking untested rookies with them on this tour every year, and have won all but one game since 2002, only dropping one match against the barbarians last year.
Donald is the best goal kicker out of this group (although hes no stranger to having a shocker), hes a great defender, he can run hard and has a long punt when given space.
However, Cruden is just as good on defense, they are both great defensively. Donald is probably the worst attacker out of the whole bunch too, his instincts aren't as sharp as the other options. He doesn't clue on to attacking opportunities as quickly as the others and he can look very labored in his play. Even when he does spot gaps, his pace off the mark isn't up there with the other 3. In situations where Cruden, Slade and Delaney scythe through holes untouched with their acceleration, Donald is often slower to those opportunity's but breaks through those closing gaps with his immense strength. He can get away with that at ITM and Super 14 level but you just can't do that at international level.
The worst part about Donalds game is that he just doesn't appear to have enough time when he does things, hes the kind of first five that looks like you could blitz on and he would flake out. He cant set up players as well as the others can either, his play making and decision taking on the fly and in broken play just isn't at the right level for the kind of game the allblacks play.
Hes a top player, but hes not really suited to All Blacks rugby.