Greenfields and Hills are never a good mix in my opinion. Don't get me wrong, they will do it well, just not as safe as something with a hydrostatic drive for example. There is the story somewhere of a kid actually being killed by a greenfield that took off down a hill after the chain broke, it was an old tractor model with no brakes at all though.
I'm quite sure anything is possible, From memory the evolution has a disk brake anyway, and I'm pretty sure what you are describing is all greenfield actually did. I don't think you would wear through a disk but pads might be fairly common
