That's right. 

So there were actually 11,000 Greek troops and 25-30,000 from the Commonwealth. 

The wider situation involves the fall of Greece itself, where thousands of Commonwealth soldiers were evacuated from the mainland to Crete, presenting Allied command with some very muddled units (though not in all cases) with mixed equipment. A good ten thousand of them didn't have weapons to fight with. Throw into mix thousands of Cretans. 

Obviously the various nationalities had their own units, including : the New Zealand 2nd Division, the 6th Brigade and division headquarters; the Australian 19th Brigade Group; and the British 14th Infantry Brigade. 

In the RP, players form a mixed-nationality platoon that's been created from a range shattered units and Cretan nationals to bolster the defences. An auxiliary platoon, if you will.