You have to remember that VG/PT get better ammo/heat management with AOE damage from actual raids (similar to Focus generation for Vig Guardians). You will perform better during an actual boss fight, so as long as you've got the optimal rotation down for this spec, you'll most likely be able to pull it off in a raid scenario, especially if you're doing fine with resource management for the first 500k damage. I can understand wanting to have a sustainable rotation on the dummy as well. You could break down the parse he posted in the guide and follow it in 15 second increments to see when he substitutes HS in for other abilities.
Im actuallr replacing said parse soon-ish (It was a terrible parse where lag screwed with me). For now, Battkt's parse on the leaderboard would be what to look at, as it was his parse that got me using mortar volley in my tactics rotation, and its his rotation I put in the guide