How Many Corp Book

We are in the process of implementing FA in our company. We have already implemented AP\AR\PO\OM\GL India Localization and smoothly running for last few years.In this scenario we want to Roll out.

2 Ledgers, (20 OU associated with L1) and (10 OU associated with L2) and each OU is defined as B/S value

Do we need to define 2 Corp for each Ledger or is there a way to use one CORP book to capitalize the asset at LE level

Should we define Asset Book at each OU level.

Which is the best practice to follow

Thanks in advance