It's not "99% theoretically impossible". Actually as uncivs go Panjab is quite strong. You do however need some luck in that the UK can't attack you too early or too often.
However once you have time to tech up it's not that bad. Just long and tedious.
I was talking about Liberia with the "99% theoretically impossible". Panjab has a lot of threats, but also a lot of advantages.