General

Spin Driver for 2-3 seconds
Then Grand Rolling Cross to Wind Cutter
Switch to Flash Cut (weapon throw) and finally finish off with Earth Break

Rinse and repeat.

I use this combo for training and I think it will work well for bosses too:
Beta: Advanced Earth Break -> Tag to Alpha with Advanced Storm Break -> Advanced Spin Cutter -> Advanced Rolling Assault (after Rolling Cross, come back in the opposite direction like a boomerang) -> Tag to Beta with Advanced Earth Break.

With that combo, I never had to use one single HP potion while training at SH for 4 hours since they heal a lot while tagged out. Sorry if it sounds difficult, but it really is only like 4 skills and 1 movement.

If your following that dpm chart, its wrong. Unless you can get throwing weapon to hit the enemy AT ALL TIMES, you should just stick with the last 2 skills of alpha and beta, maybe throw in a 3 on alpha or beta and a 2 on alpha while tagged of course.

If the boss does summons, use the first move of Alpha's combination 4 but don't do the rest to generate lots of tornados.

Alpha should use Combination 4 -> Combination 2 or 3; Beta should cycle between Combination 2 and 4. If you have more than 150% boss, Beta should use Combination 1 instead of 2.

I have been wondering this too,
honestly I have just been tagging and assisting my skills, sort of mashing my alpha and beta controls from time to time....
lol