To me it sounds like you should go for single ear with multiple web modules. See the official docs: http://maven.apache.org/plugins/maven-ear-plugin/modules.html
As you would still use SOA the web services could communicate between each other via whatever interface defined, just deployment could be simplified dramatically.
Your project pom.xmls could look like this:
WebModuleA with pom.xml like:
<groupId>???</groupId>
<artifactId>webModuleA</artifactId>
<version>???</version>
<type>war</type>
<dependencies>
<dependency>
<groupId>???</groupId>
<artifactId>payment-service</artifactId>
<version>1.1.9</version>
<type>jar</type>
</dependency>
...
webModuleB with pom.xml like:
<groupId>???</groupId>
<artifactId>webModuleB</artifactId>
<version>???</version>
<type>war</type>
<dependencies>
<dependency>
<groupId>???</groupId>
<artifactId>payment-service</artifactId>
<version>1.1.9</version>
<type>jar</type>
</dependency>
...
payment-service with pom.xml like:
<groupId>???</groupId>
<artifactId>payment-service</artifactId>
<version>1.1.9</version>
<type>jar</type>
...
and finally, the earModule that would contain all the web modules:
<groupId>???</groupId>
<artifactId>earModule</artifactId>
<version>???</version>
<type>ear</type>
<dependencies>
<dependency>
<groupId>???</groupId>
<artifactId>webModuleA</artifactId>
<version>???</version>
<type>war</type>
</dependency>
<dependency>
<groupId>???</groupId>
<artifactId>webModuleB</artifactId>
<version>???</version>
<type>war</type>
</dependency>
...
<plugin>
<artifactId>maven-ear-plugin</artifactId>
<version>2.8</version>
<configuration>
<modules>
<webModule>
<groupId>???</groupId>
<artifactId>webModuleA</artifactId>
</webModule>
<webModule>
<groupId>???</groupId>
<artifactId>webModuleA</artifactId>
</webModule>
...
</modules>
</configuration>
</plugin>
That should be basically it.
Moreover, if you want to prevent having payment-service packaged in the each war webModuleX (to reduce the size of the final ear archive), make sure to go for so called "skinny wars": http://maven.apache.org/plugins/maven-ear-plugin/examples/skinny-wars.html
Feel free to ask in detail, if some of the suggestions is unclear or inaccurate.