I don't recommend using the caching features over a true caching plugin such as W3 Total Cache, also if you are using the Falcon Cache and attempt to use a caching plugin with it, you are very likely to break not only the plugin but your website.  However, that being said WordFence makes it easy to add a strong firewall to your website even though it can be quite a resource hog at times the plugin has risen to the top of the repository for a reason and I am glad to see such a plugin is providing protection for thousands of websites.