Use
You can manage the mean value of two depreciation methods in a derived depreciation area that links the values of the two depreciation areas. In order to do so, you have to identify the derived depreciation area as a mean value area. Instead of using the arithmetic mean, you can also link the areas proportionally.
Linking formula for the mean value:
Depreciation = (depreciation in area 1) / 2 + (depreciation in area 2) / 2
Depreciation in area 1: 300
Depreciation in area 2: 100
Formula: (depreciation in area 1) / 2 + (depreciation in area 2) / 2
Depreciation = 300 / 2 + 100 / 2 = 200