The Spirit Realm

No, that's not how it works.

Haste stacking has nothing to do with slot, really.

There are 3.5 kinds of haste effects (not counting haste items). None of them stack within their category, but all three categories do stack with each other. The spells -may- coexist within each category, by standard spell stacking rules, but you'll still only get the highest haste.

"V1" or "Normal" haste effects: Comprising the vast majority of haste effects, these include enchanter haste, shaman haste (which -is- enchanter haste, for the most part), and every pet haste that I am aware of, including spirit quickening.

"V2" haste effects: As far as I know, the only V2 haste effects in the game are a couple of aging bard songs (, for example). This is -not- overcap haste. It's just a stacking form of normal haste. So someone with a 35% haste item, 60% v1 haste, and 5% v2 haste would be 100% hasted, but someone with a 40% haste item, 60% v1 haste, and 5% v2 haste would still only be 100% hasted (Haste cap.)

"V3" haste effects, or "overcap haste": Some bard songs, and a few clickies. You all the know the deal with this stuff. It stacks with V1 and V2, and it goes over the cap (but only up to the overhaste cap.). But still, only the best overhaste works.

The ".5" is the "Hundred Hands Effect" that some disciplines and the like have. It's apparently a direct delay reduction in some fashion and stacks with all forms of haste, but I don't really know how it works.