What I don’t like is reducing the Control Center. It just adds another confusing level and in my opinion, users want to configure HTTP Server and FTP Server rather than edit the apache2 and vsftpd services. The configuration names tell a lot more than the runlevel service names. Some configuration modules (FTP) also allow to choose from more services to configure (either vsftpd or pure-ftpd).

Some services don’t seem to be connected with their configuration modules or their names are confusing (package: bind, service: named, configuration: DNS Server).

Additionally, as mentioned above, the configuration module itself makes sure that all the needed packages are installed while the service is configured. On the other hand your idea doesn’t allow to even start the configuration module before the service is installed with all its dependencies (just because it’s missing in menu).

I find the idea quite useful for reducing the number of YaST modules
It is useful even without reducing the number of modules.
And anyway, I think that we do not want to reduce the number of modules. You probably mean to reduce the confusion created by having an overwhelming number of icons in the control center.

On the implementation front, I imagine an entry in the LSB comment block of /etc/init.d/apache2, like # X-YaST-package: yast2-http-server where it could pull in the rpm if not installed yet, and find the module from its desktop file, or use an additional # X-YaST-module: http-server.