Staging areas are good for sending out units to help alliance members, but they only last 24 hours. I think there should be a more permanent staging are, that could cost money.
Small warehouse: Doesn't generate calls, stores 10 units of all types. Costs $25,000.
Large warehouse: Doesn't generate calls, stores 50 units of all types. Costs $80,000.
These could be used to store reserve/backup units or to store units far away so they can quickly assist alliance members.
This would still act as a staging post, vehicles still have a home station. It is just a more permanent staging area for storing units for longer times.
I also have an image concept for it.