Looking for clarification on the mechanisms of troop movement in Warlight!

Let's say me and my opponent both have a stack of 10 bordering each other. On the first turn, I move new troops of 5 into my territory, and he attacks with his 9. Which of my troops does he kill, from the stack of 10, or the transfer of 5? I.e. When I attack back, do I have the full complement of 9 to attack with, or just the remnants of however many he killed?

If he kills my stack, then I will have less than 9 to work with, if he kills from my 5 transfer, then I can potentially still use that full group of troops. anyone know how this works?

Transferred armies always die first :)

Thanks a lot Muli!! Much appreciated :)