Money in university budgets is most certainly not fungible. Endowments are for the most part directed for specific uses and cannot be used outside of the restrictions. Education and General (E&G, terminology varies between institutions) includes tuition (only part of the yearly budget) and cannot be used for research. Unrestricted funds are as rare as hens teeth and doubly so outside upper admin.

The “color of money” is perhaps the most misunderstood aspect of university admin but explains so much about how things operate.