I have found two possible ways of changing jboss deployment sequence. If you know more, share with us.

1) Edit "org.jboss.deployment.MainDeployer-xmbean.xml" file, which can be found
on "jboss-4.2.2.GA\server\default\conf\xmdesc" directory.

Inside the file you have a line like this
"100:deployer,100:deployer.xml,200:sar,200:service.xml,300:rar,300:ds.xml,500:jar,600:war,600:wsr,600:ear,700:zip,900:last"

This section defines the priority or sequence of *.sar for example before *.rar.
You can switch between *.sar to be 700 for example and it will run after deploying the war.
I would use it only for test environment but not for deployment or release.
Choosing this option for my opinion is not a good design.

2) In case you have a jboss service like i did as a "SAR" file, you can add a dependency tags into
the "jboss-service.xml" file. For example:
jboss:service=invoker,type=jrmp


Have a good day,
Dor