It appears to me there are a few people here who seem to be somewhat deluded as to the reality of the Qantas group. Qantas, Jetstar, Eastern and Sunstate are all separate companies, hence no reciprocal employment entitlements exist between the four (with exception to the QF/JQ MOU), in both good times and bad. That's the way QF wants it to be....
Who remembers when the 30 or so Impulse pilots were retrenched a few years back? Basically they were booted (with a right of return clause), and given the opportunity to apply for employment at Eastern. Employment was conditional upon successful completion of the Eastern recruitment process at the time (Sim + interview) and positions being available.
In order to maintain consistency, I can not see why it would (or should) be any different for any other pilot in any of the group companies (under the current circumstances). Sure, give them a shot - however they will still need to complete whatever processes that the target airline requires (assuming there are vacancies).
From what I understand, Eastern and Sunstate are VERY bottom-heavy at the moment.
Lots of luck!