One thing that chafes me about infiltrators is no matter how good you are you never just get to stab someone who is completely defenseless, they always manage to grab a dagger last second, making it damn hard to stab accomplished swordsmen. If you are the top infil around and your skill is maxed or damn near it, you should once in a while catch someone completely off guard and stab the living daylights out of them. Frankly infils are shockingly incompetent. Not one has ever killed a noble, and not one has ever completely surprised a noble, due to mechanics.