In many national legislations, there's no such thing as seniority. Length of service could be factored in one way or another when making the hard decisions, but not in every country and usually not as the sole criterion but as one of many. As no internal policy of the company can override the national legislation of wherever the contract was signed, it leaves the decision makers with little choice.
Although I am very sorry for everyone affected, this sort of matrix was still more of a fair game, as compared to what the magenta brigade did a bit further eastbound (again, making use of loopholes in national legislations which allow for redundancy criteria to be as simple as "I don't like you"). At least it was somewhat more of a transparent process in Germany, with the law overriding any hard feelings middle management might have had for any locally-based employee.