If I put an absorb stamina enchant on both of my duel weapons will that double the chances of it procing ??
No, while trying to balance, our DEVs unfortunatelly missed the mechanism of global-cool-down they coded into the game and decided to ignore playerfeedback regarding the issue. So now you are doomed with either using different enchants on each weapon, both less then half as effective as a single glyph on a 2h-weapon (proccing off-hand weapons isn't 50% chance)or using the same enchant on both weapons and live with a even bigger nerf due to gdc.
Extending the previous answer - each enchant type (type, not individual enchantment) shares global cooldown. If absorb enchantment on your main hand proc'd and went on its four second cooldown - then the absorb on the off hand will not be able to proc either until those four seconds are out. Worse yet, if you have non-infused absorb (4s cooldown) and infused one (2s cooldown) on the other hand, then, should non-infused one proc first, the infused one also goes on four second cooldown. So no, don't put same enchantments on any of your weapons, they sadly all must be different.