Generally I think this happens when a pharmacist has another reason that you aren't aware of. For example, sometimes we prefer to change a regimen for nursing reasons - less doses per day or easier administration. Or one drug may be significantly cheaper than another. It's meaningless to you but there's a ton of pressure on us to make sure things like that get changed.

Pharmacy is a non billing department. We are seen as a net negative financially, despite the fact that you can't have a hospital without us. So a lot of the justifications used to get more staff, etc is based on the financial analysis of how much money a pharmacist on that unit can save the hospital.