Cannot define execution order explicitly

<plugins>
  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-dependency-plugin</artifactId>
    <executions>
      <execution>
        <id>copy-dependencies</id>
        <phase>package</phase>
        <goals>
          <goal>copy-dependencies</goal>
        </goals>
        <configuration>
          <outputDirectory>${project.build.directory}/thirdparty</outputDirectory>
          <stripVersion>true</stripVersion>
        </configuration>
      </execution>
    </executions>
  </plugin>
  <plugin>
    <artifactId>maven-antrun-plugin</artifactId>
    <executions>
      <execution>
        <phase>package</phase>
        <goals>
          <goal>run</goal>
        </goals>
        <configuration>
          <tasks>
            <ant antfile="ant/build-concat.xml"/>
          </tasks>
        </configuration>
      </execution>
    </executions>
  </plugin>
</plugins>