Forget anyone at UKBA having any kind of HEART !!!

It just does not work that way.

Like all civil servants (I used to be one) they're covering their backs from starting work to finishing. Humanity has NOTHING to do with it.

Apply for the dependent's visa as soon as you're confident you have satisfied absolutely all the requirements for the application, would be my advice.

(It is not abnormal for Spouse visa applicants with kids to submit a Dependent visa application at the same time anyway).