I seriously question a publisher that tries to make these kind of rules that are difficult to achieve or even understand. Why? May I ask who is requiring it, and I will avoid publishing there!
There are many options of how to order citations defined in the output style (see attached image for where those settings are) and they don’t need to be the same as the sorting in the bibliography, where similar settings can be defined. You can get close with # of Authors + Author then Year, but it won’t sort the more than 3 as you describe, as it will continue to sort them by number of authors then alphbetically and finally year.
You could use and sort on a custom field and put some numbers in it to override these setting, but you will need to order them manually, but in my humble opinion, if editors want to define such nonsensical demands, they should editorial manage the citations before they publish. They probably have some in house “script” to do it, I guess.
