You need to rethink your analogy. A 10 foot long (giant sized) deer at 110 yards (330 feet) covers an angle from nose to tail of .0303 radians = 1.73 degrees. That is the target the Olympian shooters were trying to hit. And even if the shot was within the 6' x 10' rectangle covering the deer, there would be a less than 50% chance of actually striking the deer's body. The limo at z153 was 21 feet long and was 130 feet from the rifle. It covered an angle of 21/130= .16 radians = 9.25 degrees and if the shot was within a 21' x 7' rectangle covering the car, there would have been a 100% chance of it striking the car. So it would be much less likely for a shooter to miss the entire car, let alone the entire road.
On a minor point, Oswald was not looking at right angles to the limousine, which would give a 21 foot wide target, but at an angle, as I recall of 27 degrees. Assuming a 21 foot long limousine with the rear being 3 feet wide (just a guess on my part), that would give a vertical target 'height' of 9.5 + 2.7 or 12.2 feet.
On another minor point, the limousine is not as wide as it is long so certainly a miss to the right by five feet would miss by the entire limousine.
The most major point is the angular speed of the 'Running Deer' target is 3.2 degrees per second. The angular speed of the limousine at z152 is 4.8 degrees per second. I don't think this means the amount an aimed shot would be off would be increased by 50%. The expected or average amount of error in the aim might be doubled or tripled or more. We don't know.
What is known that a target of 3.2 degrees per second was enough to greatly throw off the aim some of the world's best shots (in 1908). Some were able to do fairly well. Others generally missed by a lot. Perhaps all of them would have been very wild with their aims if the target was moving at 4.8 degrees per second. And that seems even more likely for a person like Oswald who never fired at a moving target before with a rifle.
In any case, what you imagine what would happen to the aim at a target moving at 4.8 degrees per second, nor what I imagine what would happen to the aim at a target moving at 4.8 degrees per second, tells us nothing. This could only be decided by real world tests with real world shooters. Ideally with shooters who had similar training as Oswald had at stationary targets but no experience at a moving target.
Assuming some of best shooters (some of the lower scorers in the 1908 Olympics) in the world in 1908 would have a median angular error of 0.3 degrees (miss by 2 feet), while someone with very good training at stationary targets, but no training at moving targets with a rifle would have a median angular error of 0.6 degrees per second, in a Running Deer competition.
If those tests were run with such shooters, perhaps we would discover that the angular error would be:
target moving at 3.2 degrees per second, causes an median error of 0.6 degrees.
target moving at 4.8 degrees per second, causes an median error of 1.0 degrees.
Or maybe we might discover:
target moving at 3.2 degrees per second, causes an median error of 0.6 degrees.
target moving at 4.8 degrees per second, causes an median error of 2.0 degrees.
which would be enough to miss the target by 6 feet at z152, which is enough to miss the limousine entirely if the miss was to the right.
In any case, we cannot say it is wildly unlikely that Oswald would not have had a good chance of missing the entire limousine at z152. We can only do so if the appropriate tests were run and the firing accuracy was surprisingly good (to me) with shooters without moving target experience.
