I don't think their confusion was on how numerical comparisons work, it was on how a "maximum term of imprisonment" could also come with a minimum duration. In other words, what does a "maximum term" mean if it's not the actual longest time someone could be imprisoned for? Are there lesser terms?
Right. The confusion here is that this document isn't setting some maximum term, it's providing a constraints for multiple implementations of the law - it mandates that whatever maximum term any given country chooses, it must be no less than one year.