Re: Will government idiots never learn? They might have to be taught by example
I'd suggest that it means neither group are all that bothered with absolute accuracy (or as near to as possible) Lets face it do the US army really care where their shells/missiles land? Based on their performance since 9/11 I'd suggest not (and that appears to apply to most allied armed forces too).
As for blacksmiths, well the process of fettling matters and can be used to make a forged peice fit, and you can always weld on an extra bit if appropiate etc, there are ways to make things work and add/remove materials
However context matters, and when talking about maths and crypto, preciseness and accuracy matter a lot (which was the point of the joke). You cant just make up the rules of maths to suit your needs in such situations where you care or there is the potential to introduce large gaping security holes. (or in the case of Nasa forgetting the change between Imperial/Metric, losing a multimillion probe to mars another good example of preciseness/accuracy mattering)