First of all, the Sukhoi SU-25 Frogfoot and other similar eastern hardware were built for a head-on type of battle which is why they were made big, bulky and not as maneuverable. Simple and tough as they may be, they are not as reliable for our intentions and purposes.
The A-10 and the OV-10 are from similar families but were both designed for other purposes than dogfights. Hence, the A in A-10 for ATTACK (ground attack) and OV in OV-10 for Observation/Reconnaissance. Now the A-10 was built with armor in mind because it was meant to swoop really low and attack bunkers and tanks. It was also meant to survive harsh anti-aircraft fire and can even fly back with most of its wings blown off. Although jet-powered, it flew slow with a distinctive whine since it allowed pilots to confirm their hits with their nose cannon or rockets before they peeled off. This was technology for the 80's. Now we have smart ordnance and laser/gps guided hardware. These A-10s by the way, are fuel guzzlers. The OV-10 suits our needs just right since we have to fight an insurgency situation deeply rooted and dependent on the masses versus the wars of the west which are more often than not against a more conventional enemy (based on their tactics).
