I didn't write any scripts, just to be clear about that.
Anyway, if you truly wish to decrease load on the ONE network, then why not go ahead and install the whole nagios on each of the nodes, including apache.
Or, do as Son pointed out, and use mini setups, all sending to central server.
What I am setting up now, is full nagios setups on each network segment, and each is sending to central server. In time, the central server will be 100% passive, getting all check result data from the worker bees.