A change in guard wouldn't be easy
The Andrew Strauss - Andy Flower partnership has provided England with highly successful and even emotional moments
They (Strauss and Flower) are two remarkably impressive men, 21st-century upgrades of Gary Cooper's strong, silent type. They calmly cleaned up one Kevin Pietersen mess in 2009, and have shown exceptional dignity in the face of another, even if a few lunatics think it is time for both of them to resign. Their success (and recent travails) have created a bond we would expect to last a lifetime. All of which makes their parting even harder to comprehend.
In an ideal world they will simultaneously come to the conclusion that it is time for Strauss to be replaced by Alastair Cook, but sport does not always provide such neat endings. What if Flower feels that Strauss's batting form is no longer sustainable? Flower is a disciple of eye contact but if he has to have that conversation with Strauss, even he might feel like focussing on the eyebrows rather than the eyes.