Must I make up the missed Dhuhr and Asr prayers together, or is it permissible to make up Dhuhr before Maghrib and then make up Asr after Isha, bearing in mind the obligation to arrange missed prayers in their proper order?

When the Dhuhr and Asr prayers are missed together, they must be made up immediately and in order. However, if the time remaining before Maghrib is only sufficient for Dhuhr, you should pray Dhuhr, then Maghrib, then Asr. This is because the obligation of observing the sequence (tartib) is waived when there is a fear of the time for the current obligatory prayer expiring. The Malikis hold that both Dhuhr and Asr must be made up together, even if the time for the Maghrib prayer has passed. A missed prayer must be made up immediately, and it is not permissible to delay it if one is able to perform it.