I tried those after I stopped getting skillups in Attohwa, but there were two things working against me: some guy kept rounding them up to kill them (presumably to get NM pop items), and I had a bad run-in with the NM cactuar. He gave me great skillups until I ate about 35,000 needles in one shot.
Yeah, you'd wanna avoid the cactus (I never had trouble with it, since he's kinda tall and easily noticed). And although there are people who AoE those mandies because they're plentiful and easy to train, it isn't happening all the time.
If you do aggro Cuijatender somehow, it's possible to just run like **** and deaggro it, because he stops to cast stuff.
This was the spot I used to cap my own shield skill, which took about 40 minutes to gain about 150 levels... Ochain is a beast >______>