Until this is fixed (JBT 4.0.0.Beta1), here's a workaround for you :
- right click on the sar dependency
- click on Project Facets, convert to Faceted form
- add the Utility Facet.
- repeat for all your sar dependencies
- in the navigator view, open <sar-project>/.settings/org.eclipse.wst.common.component and remove all <dependent-module>s
- update the maven configuration of <sar-project>