Shielding Hands & Protective Spirit

So does the damage get cut down to 10% max health and then reduced by 15 (at protection 12) or the other way around?
Or can you influence this depending on the order you cast the enchantments?

I believe this is influenced by the order in which you cast them.

can anyone back this up? this would make for a powerful combo if true

I read it off the Guild Wars site, just so the math ahead of battle to know which to use. So if someone normally hits for 10 damage, and you have two skills that reduce damage by 10% and by 5 damage, it would be better to use the 10% first then the 5 damage. Just matters for what the skill does and what the enemy has (hp, damage, armor, etc.). Usually it won't make that much of a difference, but after playing for a while you will more than likely get used to it and know when to use which.