I don't remember if this has been suggested. But why can't you assign a "depot unit"(to manage things like websites, museums and service clubs, etc)to each regiment. So far this is nothing unique, but heres the catch. When it is desired to reduce expenditure, instead of the distasteful custom of "amalgamations", you can reduce it to the depot unit, and leave it in place to rebuild a regiment around it, next time that becomes necessary. For instance suppose Emperor Palpitine declares himself Dictator of Europe, and it is decided that there is a fair chance of hostilities in the next ten years. You raise a training unit around each regiment, and use that to build up an army. When the crisis is past, you reduce some regiments by a given amount. Some would be reduced until they in effect, notational. But those notational("depot") units will remain in case it is desired to fill them up again. This process can go on ad-infinitum.
The point is that they would remain on the rolls, with their traditions intact, etc. It would be a army equiv to what the US Navy has been doing with World War II Battleships.