There are several issues:
1) A regimental list - Number relates to earliest in regiment. Change regiment, you have a different number (or no number at all!).
2) Field-grade officers. I believe these numbers relate to one's entry into the Field-grade rank.
3) General officers. I believe these numbers relate to one's entry into the General-grade rank.
4) Host (or non-Russian ranks). Same as regimental list with an additional Host rank list by possible date of entrance as being determinative.
5) Host (or non-Russian units) with Russian ranks. Goes back to 1-3 above within the Russian rank system.
I am quite interested in what Oliver might say regarding the Prussians. The Russians system appears to be based upon the Prussian one.
I am not at my residence at the moment. I will have to secure examples of each of these statements and then post them.