With regard to the "cross draw" technique, that method of deploying a weapon can be traced back to Biblical times. The following passages are from
Judges, Chapter 3. Verse 21 shows that Ehud, who was left-handed, favored the "cross draw."
[size=10]12 The children of Israel again did that which was evil in the sight of Yahweh: and Yahweh strengthened Eglon the king of Moab against Israel, because they had done that which was evil in the sight of Yahweh.
13 He gathered to him the children of Ammon and Amalek; and he went and struck Israel, and they possessed the city of palm trees.
14 The children of Israel served Eglon the king of Moab eighteen years.
15 But when the children of Israel cried to Yahweh, Yahweh raised them up a savior, Ehud the son of Gera, the Benjamite, a man left-handed. The children of Israel sent tribute by him to Eglon the king of Moab.
16 Ehud made him a sword which had two edges, a cubit in length; and he girded it under his clothing on his right thigh.
17 He offered the tribute to Eglon king of Moab: now Eglon was a very fat man.
18 When he had made an end of offering the tribute, he sent away the people who bore the tribute.
19 But he himself turned back from the quarries that were by Gilgal, and said, "I have a secret errand to you, king." The king said, "Keep silence!" All who stood by him went out from him.
20 Ehud came to him; and he was sitting by himself alone in the cool upper room. Ehud said, "I have a message from God to you." He arose out of his seat.
21 Ehud put forth his left hand, and took the sword from his right thigh, and thrust it into his body:
22 and the haft also went in after the blade; and the fat closed on the blade, for he didn't draw the sword out of his body; and it came out behind.
23 Then Ehud went forth into the porch, and shut the doors of the upper room on him, and locked them.
24 Now when he was gone out, his servants came; and they saw, and behold, the doors of the upper room were locked; and they said, "Surely he is covering his feet in the upper chamber."
25 They waited until they were ashamed; and behold, he didn't open the doors of the upper room: therefore they took the key, and opened them, and behold, their lord was fallen down dead on the earth.
26 Ehud escaped while they waited, and passed beyond the quarries, and escaped to Seirah.
27 It happened, when he had come, that he blew a trumpet in the hill country of Ephraim; and the children of Israel went down with him from the hill country, and he before them.
28 He said to them, "Follow me; for Yahweh has delivered your enemies the Moabites into your hand." They followed him, and took the fords of the Jordan against the Moabites, and didn't allow any man to pass over.[/size]
Of course, Ehud was using a sword said to be "a cubit in length." The length of a cubit at the time is a subject of some scholarly debate, but Ehud's sword was probably between 20 to 30 inches long (more likely near 30 inches, since Eglon is reported to have been "a very fat man" and the sword pierced him through). The longer the sword, the more natural -- even essential -- it is to deploy it using the "cross-draw" technique. Nonetheless, ever since handguns were first developed, there have been some individuals for whom the "cross-draw" has proven to be the most effective means for deploying them.
"Different strokes for different folks."