HI Ardy,
Business Content installation is the easy way but not always sufficient. I always consider it as a (very welcome) starting point and depending on your ambition level you can reuse it and/or enhance it to meet particular Data Warehousing standards or architecture guidelines.
Following an LSA approach, I suggest to introduce an intermediate Propagation layer where you have a standard DSO for every DataSource (with key fields corresponding to your DataSource source tables). Optionally you could have a Corporate Memory DSO (write-optimized) for every DataSource.
The Consolidated DSO I would position in the Business Transformation layer. You will have to analyze very well if indeed special Transformation rules (especially routines) can be found in the Transformations from DataSource to the Consolidated DSO. You will have to recreate / copy such Transformation rules to the new corresponding Transformation from Propagation DSO to Consolidated DSO.
Best regards,
Sander