The arm drag to single leg is one of the safest, highest-percentage takedowns in wrestling. You are not shooting blind into space. You are controlling your opponent's arm first, then attacking a leg that has no defense.
Jon Trenge teaches the inside chop drag specifically for this. Chop at the wrist, catch above the elbow, but instead of circling your head around to the outside, keep your head on the inside. Your right ear goes straight to his bicep. Then you weld that arm tight against your neck and drive down to the thigh.
Here is the key detail most people miss. Once you hook the leg, his arm is stuck against your neck and you have his leg. All you need to do is push his weight onto his free leg. That leg gets light and comes right up where you want it. Trenge calls this "super low risk — there is no risk to it."
He also teaches a version from a tight collar tie. Grab the wrist with your thumb on the outside, step around, catch above the elbow, and slide your head away from his head while driving your hip into his hip. From there, bring your back foot up, pop your hips into him, and take him down.
For the full takedown system including outside drags, circle drags, and finishing sequences, check out our complete guide to wrestling takedowns. Get the full course in Jon Trenge's Complete Wrestling System.