When creating a fixed asset there are things that are usually consistent for assets of the same subclass. These can include but aren't limited to:

No. Series

Depreciation Method

No. of Depreciation Years

Dimension settings

On an asset subclass you can provide defaults for class and posting group but nothing else. The asset subclass could be extended to add in additional defaults.

Alternatively, Fixed Asset Templates could be added, with the defaults working in the same way as the customer and vendor templates. This would seem a more consistent option across other modules and would allow for greater flexibility on dimensions and no series defaults.