I'd say they're about the same, but the 260x is more overclockable.
Also, it has a better clock speed, more video RAM and better RAM clock speed (Not that it means that much)
I don't know that much about the 750, though.
No, the system requirements for that game are very high. For maximum settings an r9 290x is recommended! You might be able to play on low/medium. Have a look on YouTube and see what other people are getting, it depends on what your other components are too...
I'd say they're about the same, but the 260x is more overclockable.
Also, it has a better clock speed, more video RAM and better RAM clock speed (Not that it means that much)
I don't know that much about the 750, though.