Retired military expert pistol and rifle during active duty. Decided to get a gun for the first time in my life last month. My XD-M has a knurled grip on the front edge of the trigger. My previous training with a 1911 .45 APC did not have a place to grip on the trigger guard. Is that intended to use my left hand index to hold that versus under the trigger guard which is more like the previous training I had in the military