Most definitely the intention is not to be transparent. The reason why this was not addressed at this stage is that it can be technically complicated.
Crossed lines is a situation that can occur in various environments, as you pointed out. It's probably not that common at the start of a process, but it might become more prevalent in situations of maintenance, because very slight changes might make the lines cross.
The regulations will adhere to the principles of the legislation and make sure that all of those female-predominant jobs in the portion of the lines where the female-predominant line is below the amount of a male-predominant line will be addressed appropriately.