The thing is, having aggressive players at the top of the order has never really worked for us. I thought CK did OK when he was there, but we've done better since Bell came in. Most of the games where the 3rd trend occurred for Trott were either away from home or when we had an understrength bowling attack. In the Champions Trophy that isn't going to be the case, at least the former certainly, and hopefully the latter. Trott played 9 completed ODI's last summer, against a wide variety of teams, who were all reasonably strong, and we won 8 of them, mostly because our bowling attack did well.
If KP comes in for Root at 4 for the Champions Trophy we'll have slightly more power, while being in the conditions where a powerful top order is needed least. I think our current side, with KP in for Root, will be fine for the Champions Trophy, and that's all that we really need to be working towards at the moment IMO.