It is very long to do a query for install ten products since they contain a lot things like phrases, plugins, templates, settings, infos etc... What you could do is to 'fuse' them.. you can copy all the plugin and the other things of each xml and put them in one unique xml. Or i don't know if is it possible but you can even try to copy all the product tag of a xml and copy it at the end of another xml. Just like this
Code:
<?xml version="1.0" encoding="ISO-8859-1"?>
<product productid="product1" active="1">
All the code of the product One
</product>
<product productid="product2" active="1">
All the code of the product Two
</product>