The phrase "a patchwork of federal" is correct and usable in written English.
It can be used to describe a situation or system that is made up of various federal elements or components that may not be uniform or cohesive.
Example: "The healthcare system in the country is a patchwork of federal regulations and state laws, leading to inconsistencies in patient care."
Alternatives: "a mosaic of federal" or "a blend of federal".
— Rene Sweepstakes, contests and lotteries are governed by a patchwork of federal and state laws.
Instead, we have a patchwork of federal and state authorities scrutinizing these technologies.
The current financing for the network of independent programs comes from a patchwork of federal, local and private sources, including about $40 million in state money.
Though the financial crisis was global, it originated in America's uniquely fragmented financial system, overseen by a patchwork of federal and state regulators.
Ships fly under foreign flags and their parent companies are incorporated overseas, leaving regulation to a patchwork of federal, state and, rarely, local laws.
The cases have come from a patchwork of federal agencies, state officials and shareholder suits, some of which have been resolved in multibillion-dollar settlements.
The current safety oversight of the cosmetics industry is a patchwork of weak federal, state, and industry regulations.
The telecommunications providers will be subject to a motley patchwork of federal privacy law.
(American prisons operate in such a complicated patchwork of federal, state, and local jurisdictions that, as Pfaff points out, it is hard to get a good handle on the numbers).
Currently, there's a loose patchwork of federal, state and local laws that ban the ownership and selling of exotic pets, while other states lack any regulation at all.
The 43 people who headed out on a motor coach earlier this week to play slot machines at a Salton Sea casino likely had no idea they were betting their lives on what some consider an inadequate patchwork of federal and state protections.
