The multi-org question
One org is an architecture preference. It is not automatically the right answer
Multi-org estates are usually corporate history rather than architecture failure. Each acquisition arrived with an org and each had a reason, so consolidation is a decision on merit. Sometimes one org is right. Often a forced merge destroys more value than it releases.
Consolidation is right when the same customer is served by several units, when regulatory reporting spans them, or when parallel processes cost more than the merge. It is wrong when the orgs serve different regimes, models or customers who never overlap.
So we survey first and answer with a number attached, including when the answer is to leave the estate alone. We design for Salesforce Well-Architected outcomes and document how each org relates to the systems already holding parts of your truth.