WOW Power Leveling: This is my personal view on what guild wars pvp formats require
GvG is different from HA in the fact that the maps are bigger, meaning there is more room to move in and play positioning games (macro skills). Also the fact that everyone resses every 2 minutes as long as they don't have 60 dp gives more room for positioning games.
The battles last longer because of this WOW Power Leveling, and give a team more time to try out different splits after finding that the current fight isn't going favorable for them. This leads to the following table:
Again, this is my personal view on what guild wars pvp formats require. It does give a small overview for new pvp players what they can expect and need to know (and can learn) when fighting in a certain environment.
Try to coordinate your attacks to overwhelm the cast time, energy and response times of the opposing players. This is known as "spiking". See the Eternum Pariah spike videos for examples of this.
Don't use more than 1 Superior skill rune - the health penalty is too painful. There's no reason not to use minor runes of your other primary profession skills and a superior rune of vigor. Warriors will also usually want an absorption rune.