Ummm nobody said he was more well rounded (whatever that means). But the original question asked who was better away; nothing more nothing less. Ambrose played 46 tests away and had a better average, sr, wpm and econ than Imran. Your issue is he played mostly away to England and Australia. Fun fact, Imran played most of his away tests in those two countries as well. Anyway, until Australia/England magically relocate to the Caribbean basin, they count as away tests for Curtly.
He played 12 other tests outside those two countries and collectively did just fine: 12 tests, 36 wkt average of 22.97 and sr of 58. Not spectacular by any stretch but not overly poor either. By way of comparison, Imran has a worse average in all countries except for SL, worse sr with the exception of WI and SL. Imran does have a better wpm generally but it's under 4 in England and Australia. I'm not even including India because knowing how your mind works, you'll hold it against Ambrose even though he had ONE chance to play in India.
My point? Just like Ambrose there are places where Imran was moderately successful (Australia, England, NZ) but overall away, as was queried by the original topic he is inferior to sir Curtly.