The Ka-50 is very much Hide and seek against the enemy, the A-10 less so. I can't remember the amount of times in the Shark I've hurriedly crested a ridge, to find a tank gun I didn't expect pointed straight at me. BOOM!
The A-10 has a much broader view of the battlefield and can stay way above most threats, and can pick things off at leisure. The Ka-50 has to be much much more patient to get a picture of the battlefield, and only then plan a safe attack accordingly.
Nate