Yeah, I did think of that after I posted it. Still, it was apparently a running gag that Kasdan put into the script for one film. Neither 3PO or R2 mention anything about odds in the rest of the films, so this would be a good example of R1 ripping off the script from Empire.
Also, the Walkers in R1 are stupid for the reason RLM pointed out. One difference between Empire and R1 is that in Empire, the people making the movie were going balls to the wall to make it look like a realistic, futuristic battle. Sure, they wanted it to look good, but only so far as it looked real.
In R1, on the other hand, there was quite obviously zero attempt to make Scarif look like a real battle. It was conceived in much more of a comic book superhero universe kind of way.