Enchanter Debuff Stacking

[Pringles]

Something I've been pondering is when i cast cripple on a mob and asphyxiate do the debuff elements stack? Cripple does quite a bit more of a penalty to a mobs stats so is it the only one to actually affect them? Both spells will land on the same mob and the dot portion of asphyxiate works but im unsure if its also debuffing stats as well. In that same vein can you stack lower level debuff dots of the same line together?