Someone who has only done Fletcher or Cresco topdressing work could very easily have no tailwheel experience. Not all Ag planes are tail draggers.
Correct, know of any others besides that Norman thing that was demonstrator only? Even people that have only flown Fetchers most of their career have flown tailwheels with AG rating. I know of only one possible in the last thirty years who might not have had tailwheel time.
Still I spose you have to cover every possiblity. To me personally, having both been employed and employing people I would not put an add in like that.