This statement is typical hyperbole and sensational to inflame public opinion.
"This was an audacious scheme to create massive hybrid sheep species to be sold and hunted as trophies,” assistant Attorney General Todd Kim from the Justice Department’s Environment and Natural Resources Division said in a press release."
The concept of uniquely large animals to hunt is very common in the U.S. High fence whitetail deer hunting venues exist in many states. State Game and Fish Commissions maintain record books for sizes of wild harvested fish and game animals.
(I don't know all the details of this case and have not read the court proceedings. Likely more to the story than the reporter describes.)
All manner of attempts to breed larger cattle via species cross breeding occurs. Producing larger animals via chemicals is not unheard of. All designed to appeal to revenue producing activities and food products.
Game and Fish Commissions do the same thing all the time to generate revenue. Currently before the Alabama legislature is a co-sponsored bill (HB15 - 2024) which the G&F endorses - to release Florida strain largemouth bass along the Coosa River waterway. The Bill includes the term hybrids as well. These bass get much larger than native DNA strain bass and are more aggressive. Such is designed to sell more fishing licenses and generate "fishing and tourism revenue for the state". Auburn advises the G&F and private land owners on such matters and every "managed pond / lake" in Alabama will have Florida strain bass and non-native bream / sunfish. How is this any different than the sheep guy in Montana producing larger sheep? (back to the statement and independent of Lacey Act related to Marco Polo sheep). Here is the Alabama Bill - very brief in content.
https://legiscan.com/AL/text/HB15/2024
To bring the question into herptiles, in the reverse, why not allow so-called dwarf lines of larger snake species to be kept? Many states regulate by species or size. Rarely a combination of the two demographics. Or discussions of hybrid reptiles (independent of one's position on hybridizing animals).