Well tbh Shatabdi ke rake ka lifespan complete hone tak change nahi karna hi sahi decision hoge... Saare Shatabdis replace karne ke pe bohot excess AC CC coaches ho jaate unko utilise karna tough hota. But lifespan complete hone ke baad to milna hi chahiye VB rake. New LHB coaches ka koi logic hi nahi hoga in trains me jab VB rakes se speed up aur better services milenge