It's not a short leash. Next year will be Claeys 6th year at the University of Minnesota. He has been the top paid assistant at this school for 5 years, and heavily involved in recruiting. These are his players too, not just Kill's. He's not starting over.
As others mentioned before Claeys was hired full time, if this coaching search was opened up nationally, would Claeys have been the choice? Likely not. He was hired as the only in house prospect to keep continuity. This is not a new coach inheriting someone else's players. Currently the Kill/Claeys era is 15-25 in the B1G. If the Gophers go 5-4 next year, that's 20-29 over 6 years. Is that good enough?