I would not trust NADA to be accurate with available options. Their listings are usually very general in nature often showing options that were never available for a particular model. If 1 slide was indeed the standard build, then a second (bedroom?) slide could have easily been optional.
As to how many were built, I doubt anyone can give you that number.
1995 Coachmen Santara 360MB 36' w/slide.
Ford F53/460 chassis, 2020 Chev Equinox "toad"