Once, all pilots were proficient at prop swinging - they had no choice. And I'm sure the expertese was gained the hard way! And the aircraft were designed for it. The Gypsy Major is easy to hand swing - usually the prop is mounted on the crankshaft so it's natural - for a right hander anyway.
Apart from a few vintage aircraft which require it, the skill is no longer needed and has been largely lost. This should ring alarm bells in anyone going to try it without training. I was trained to do it and apporach any handswing with the appropriate level of caution. This saved me or someone else fro being maimed many years ago when my own aircraft had a flat battery. A couple of guys in the syndicate were attempting to start it and I didn't like what I saw, so I volunteered to supervise which ended up with me doing the swinging. Despite a very careful briefing to the pilot, he decided to switch mags and accidently tuned the starter. This is when discovered that the battery wasn't actually flat (it was a solenoid problem) when the engine started. Luckily, my caution prevented me being injured. If the original swinger had continued, I reckon he wouldn't have been so fortunate. As someone said, if it's designed to start with a starter and doesn't - get the engineers to sort it.
As for swinging from behind, I'm not sure how easy that would be on a Gypsy powerd aircraft. My Fournier RF3 didn't have a starter and was always swung from behind. You stood next to the cockpit with youh right hand on the throttle, swung with your left hand. When the engine was running, you pulled the chock (single main wheel) and stepped on to the wing into the cockpit. Never any drama.
Chocking is essential. However, a friend of mine who had a Chipmunk with a cartridge starter had a novel approach. He had a shotgun certificate which allowed him to buy cartridges, but used to hand swing on his own as much as possible as the cartridges were a fiver a time even in the 1980s. His aircraft had a glider tow hook. So he screwed a large auger into the ground, attached to which by a short piece of rope were a set of glider 'Otfur' rings. He hooked the Chippy to the auger, poining into wind, handswung, climbed in and when ready to taxy, just pulled the rope release. Brilliant!