The Mig-29, as with other Soviet aircraft, started its "career" in the west as artist's impressions.
Here are 3 of those, of the early 80's a time when (obviously) not much was known about this aircraft.
Aircraft Illustrations: copyright of Pilot Press Ltd Salamander Books ltd
The russians had stolen the plans (or some of them) of the YA-9 (it's said)...
(The developement of the SU 25 starts four years earlier than this of the YA-9).
The A-10 wasn't (less or more) superior over the A-9. Just further developed and the production could start earlier.