Actually, I think that's an XML change. Look at the following:
Code:
<UnitMeshGroups>
<iGroupSize>[B]3[/B]</iGroupSize>
<fMaxSpeed>1.75</fMaxSpeed>
<fPadTime>1</fPadTime>
<iMeleeWaveSize>[B]3[/B]</iMeleeWaveSize>
<iRangedWaveSize>[B]0[/B]</iRangedWaveSize>
<UnitMeshGroup>
<iRequired>[B]3[/B]</iRequired>
<EarlyArtDefineTag>ART_DEF_UNIT_LION</EarlyArtDefineTag>
</UnitMeshGroup>
</UnitMeshGroups>
The numbers in bold are the important ones. I think if you increase the "iMeleeWaveSize" and "iRangedWaveSize" to be the same as the "iGroupSize" number, they should attack as a group. I could be totally wrong. Again