Hey,
I have a couple of Pims, initially, I just had one and he was just not happy, even though there was plenty of hiding places he just went up and down the tank vertically all day and night it must of been exausting and he rubbed a little white patch on his nose.
I got a little worried about him and stuck in a second one.His behaviors changed immediatly, they swim around quite happily together and hide together and yes bicker alot together but they seem much happier. So if you want to see the most from them he might like a buddy or two
Mine are in a heavily planted 4ft tank with a gibbicep an African Knife fish (both grow big), four large clawed shrimp (but I don't recommend that, i'm gonna move mine soon) and a pair of mature kribs, I don't know why my kribs never seem to get any grief perhaps because they are quite stroppy and fast, in the past i have put them in with quite serious predators and never had problems. But that might just be me so don't take that as gospel.
My Pims also went through a growth spurt after i bought them but now they are about 3.5" and have slowed right down.
I'm no expert and I might be slated for the advice but mine have all seemed fine, hope thats some help.