Several inscription toons can do more research per day.
But it is random what you get.
So I'd probably stick with one Scribe only, anyway.

Learn everything from the trainer.
Purchase Books of Glyph mastery.
And do your research faithfully, until you don't learn anything else from it.

Use APM to scan the auction house.
And create any glyphs that you have none of, on the AH or in inventory.
Probably set it to not post a whole lot of one glyph at a time.

Maybe create glyphs once a week, or every few days.
And bulk Cancel and re-Post once or twice a day, to undercut competition.