I totally agree with you in that they are different monsters, especially since on a nine foot table you would not likely make the 3-7 or the 4-8. Those rail shots were intended to be played as short side cuts.
However, I want to give everyone a chance, so I don't really want to eliminate the bar table players. I think for Challenge 4, I might diagram two very different challenges, one for bar box and another for standard.
Thanks for the tip, I'm still working out the kinks for these challenges and eventually they will be more challenging and more consistent.
You can still complete the challenge if you like, 2nd and 3rd players to post get 2 free tshirts!