"Allied intelligence noticed each captured tank had a unique serial number. With careful observation, the Allies were able to determine the serial numbers had a pattern denoting the order of tank production. Using this data, the Allies created a mathematical model to determine the rate of German tank production. They used it to estimate that the Germans produced 255 tanks per month between the summer of 1940 and the fall of 1942."
One source of many: https://www.wired.com/2010/10/how-the-allies-used-math-again...
This information was used to estimate force size and thus counter it, and it turns out this method was surprisingly accurate.
The Russians even went further, specifically engineering their tanks to only pass QA to last a very short amount of time (as little as a few dozen KM of use) during the first half of their involvement in the war because they'd be destroyed before then on average anyways.
On that note, using UUIDs would be more 'secure' than auto incremented numbers, wouldn't it? I don't like how much space they take up in my URLs though.
Or just assign them in blocks that are out of order. Any intelligence gained from the leakage of such blocks would be misleading. Misleading is often even better than non-existent.
[1] - modern weaponry makes large-scale land war difficult to survive, e.g. the average survival time of a main battlefield tank is counted in minutes.