The OV-10 was great for the FAC role - the amount of radios, the two seat config (i know the Most flew alone) and the weapons like the 4 7,92mm MGs and the Rockets.
•Relaying the radio comunication
•observ the area
•Guide airstrikes
•and supress the Enemy untill the fastmovers arrive
Sure you can do light attack
But FAC is not less fitting for this plane