I've been pure spy all these 3 years... Damn fun.. This is my only attack build. Pure spies are, IMO, the most fun. You get to annoy and steal farm people all the time and you can do that for months without losing anything. You don't need Allies, so no one can strip farm you. All they can do is to pin you.. But they usually get tired before you do, then you can go start it all again on the same person. Pure spies *ALWAYS* win a war of attrition. Simply because they have nothing to lose...
ditto odies post pure spies are the lazy mans way to kaw "steal what you can don't give nothing back " Add some spy def towers to your kingdom and become an extra special pain in the ass