I have 5 in my tank and they all absolutely love the plants, the denser the planting the better. One of my females has even taken to using the cover of the trailing silk plant I have in my tank.
No probs whatsoever with them nibbling the plants, they just seem to love the cover they get.
you could have 1 male to 2 or 3 females (depending on tank size)
I would start off with 1 male and 2 females and see how they go and then work up but that's what I have personally found best
They love plants and small places to get into, they are bottom dwellers but occasionally they will wonder up to the middle section. Anubius on bog wood is a fab plant, esp with anubius roots, they love it!