Yes, spending less money is better than spending more money (though there can be potential tax treatment differences or other complexities depending on exactly how money is spent), but that doesn't mean the person in charge of approving an employee's expense is authorized to approve expenses however they please. If they're given a budget that says they get X money in one category and Y money in another, they can't spend (X-2Z, Y+Z) and can only choose to spend (X,Y) or deny the request. Big organizations often have a lot of inefficiencies due to process.