I'm uploaded an example pom.xml and module.gwt.xml to Gist: https://gist.github.com/NickWilton/dc1602fff24509154c076daa404bacb5
This example uses SmartGWT 4.1 and GWT 2.8.
The directory structure for this example is:
/ src / main / java / yourpackage / client
resources / yourpackage / module.gwt.xml
webapp / Your Web Files Go Here
You should be able to add the additional entry points into the module file (or have multiple module files each with a single entry point, and compile these separately).
But I suggest getting it working with one entry point for now.
I hope this helps.