I do not understand how Qantas can run Two or more airlines without them cannibalizing each other?
QANTAS are not running two airlines, they are only running one namely Jetstar.
QF mainline does not figure in future plans, QF management will just let QF mainline fade away, at least BA had the nous to jettison GO when it started having an adverse effect on their mainline European operations.
QF are doing the opposite.