Temis the Vorta wrote:
Shane was already irrational, so having it all just be jealousy doesn't add anything or more importantly, do anything for the plot going forward.
The writers admitted on last night's Talking Dead
episode that they don't even know necessarily how the season might progress.
In fact they cited an interesting example. The original plan was to kill off Herschel but they changed their minds at the last moment
In short, I think you may be giving them way too much credit for foreshadowing what may come when they don't even know themselves.