Depreciation Expense A/c default from Asset Category

I need a bit of guidance on the correct usage of Asset Categories. We define Depreciation Expense A/c and Accumulated Depreciation Expense at the Asset Category level.

Then while we define new Assets, we attach these Assets to the Asset Category.

However, the system forces us to enter a Depreciation Expense A/c in the Assignments Form. Is this the standard functionality?

How can I use the system in way which the Depreciation Expense A/c is sued from the Asset Category defenition instead of entering it each time

Thanks

Joseph