you should actually follow the steps provided in the migration document and if you have already done those steps then you should go ahead and you have to make sure that you use existing modules as module dependencies and rest of the thing you put it in war library.
Make sure that Manifest.INF which is at EAR level has the declaration of the module which you are creating or contain the list of dependencies as defined in the documentation. For me i Had the similar issues and I made it to work by using Manifest.inf file at ear level declaring the a module like you are trying and secondly defining all other common as transitive dependencies in that module. remove the modules which are in Jboss from your lib folders and for those jars add as dependencies . Do share your log file after doing that.