When using an SRX (we have a 1400) to protect a server we can create an application-ddos rule for DNS, but what if we want to protect it against SQL exploit attempts like "SaAdmin" login attempts?

In the JUNOS guide, it states,

"Note: Application-level denial-of-service (application-level DDoS) detection will not work if two rules with different application-level DDoS applications process traffic going to a single destination application server."

It's almost as if you can protect a server from only one protocol's exploits at a time. If that's not the case, how is it done? I haven't seen a single configuration for SRX IDP that shows a specific destination protected for more than a single application/protocol. What happens if you want to protect your webserver from HTTP and FTP exploits?