1. This is really a prefferance issue, but being able to 2hko Ttar is invaluable.
2. Any variant except from the Bulky Quiver Dance is ohkoed by Smack Down in the sun. Also Landorus fails to outspeed Bulky Volcarona at +1 and dies from sun boosted Fire Blast or Fire Dance. So the only way to take advantage of the ohko that Rock Slide provides against BulkRona, is if you both make a double switch, or if he brings in Volcarona after you kill something with Landorus. So realistically the only time that you will be able to kill BulkyRona with Rock Slide is when you kill something with HP Ice, and the opponent brings BulkyRona in thinking you are choiced.
So is this little tiny scenario worth losing the ability to 2hko threats like Skarmory, Rotom-w and Bronzong?
Anyway i had some battles today and yesterday and the team is very solid! Can you get in IRC to tell you a few things?