Usually discovery is served in groups, e.g. Form interrogatories, Request for Admissions, Request for Documents. If no response is provided I file a combined motion to compel these initial discovery responses. I did this after several judges told me why not combine them and save filing fees and paper. Once a judge told me not to do a combined motion only as a warning, not a denial of the motion. Nothing in the Rules of Court that I found say you cannot combine discovery motions. Here is my statutory analysis of this issue:The Rules for discovery motions are in Cal Rules of Court, Rule 3.1345. E.g. a separate statement for a motion concerning further responses or Cal Rules of Court, Rule 3.1345(d) that only says “A motion concerning interrogatories, inspection demands, or admission requests must identify the interrogatories, demands, or requests by set and number.”