BA do a separate graduate scheme for roles such as engineering, procurement, finance etc and the requirements for those are very much in line with other graduate schemes (2:1 in a relevant degree, 280+ UCAS points etc)
I agree that if they placed more weight on the academic stuff then they would specify degree or A level subjects, but seeing as they don't it can only be assumed that they use these as a general indication of academic ability rather than an essential requirement