Help with application UCAS

So I emailed uni of Sheffield about their foundation year and they said I wouldn’t normally meet their requirements with my grade 5 in maths instead of 6 but because I show strength by my grades, they consider me if there is still available places after January deadline. But with uni of Manchester, I got told I don’t have enough science content from my a level subjects? I just want to know why Sheffield are willing to accept me but not Manchester? Not bragging or anything but I just want to know the difference between the two answers I received. Thanks

Hello, it could be because UoM may have more people applying for that particular course they can be pickier with who they want and may be higher in the league tables for that course whereas UoS may be different with fewer people applying so they are more lenient and have different criteria for people who apply to give offers compared to UoM.