A low grimoire can be a means to determine experience, but not a high one. I've done vog four times total- and all in the last fortnight. Ask me two weeks ago, I'd've had a high grimoire but never set foot in the raid. I've played the game a hell if a lot but no vog experience. So you'd be better off with that 2300 grimoire level 31 with 20 vog clears than me with 2650 or whatever with no clears. And I'm not a 'bro'.