Having worked as a sysadmin and a DBA, I certainly won't dismiss your managers suggestion. Your webserver is reachable from the outside, and hence it can be compromised. Even if you have the most recent security patches installed the moment they are available. The less data is on it - the better. Replicating only the necessary data to it certainly has a lot of merit.

Now whether it is the best solution or not, I cannot judge. That depends on a lot of things, more than you can write in a short message like this. You'd have to know more about the data and the services that need to be provided. Competence of the staff is important too - I've seen too many replicating systems not functioning well because the admins didn't have the necessary knowledge.

Abigail