ideally the bladelogic schema should be in its own instance, can you confirm whether or not that is the case? if there are other schemas in this instance, then what he says about the archive logs is true. I don't know if we can determine how much archive log traffic we are going to generate or not. I know i've run into issues during upgrades when archive logs are enabled, esp if space is tight.
so he either needs to get more space for the archive logs, or be constantly monitoring that space during the upgrade so he can free it up if possible or disable archive logs an take the hit on the oher apps during the upgrade window.