If you have multi project and you define a project dependency in your web project on another project and run the eclipseWtp task then the project dependency is added like this:

<dependent-module deploy-path="/WEB-INF/lib" handle="module:/resource/platonos-lightning-core/platonos-lightning-core">
<dependency-type>
uses
</dependency-type>
</dependent-module>

If you try to deploy the web project then no jars are copied from the dependency project.
I was able to make a workaround by modifying the generated org.eclipse.wst.common.component file.
I throw away the dependent-module nodes rebuild it. I collect all dependencies, most are coming from the gradle cache,
but some are from the 'build/libs' directory in the projects. In this way you don't have to upload them first.
If you change something in a project then you can simply build the project and refresh the web project in Eclipse
and wtp will deploy the changed jar(s).

I guess that there may be situations that the excisting eclipseWtp task works fine, maybe for enterprise applications instead of a simple war application. So the current behavior could be the default behavior and other could be configured.