Seems to me like the smaller pictus are more active and as they age they become more and more of a hiding fish that comes out at night.
I have 4 currently. 3 of them are about 3 or 4 inches, and they hide most of the day. And one 2" er who swims around almost all day.
One thing to remember is that they have stickers, so if one of your larger cichlids decides to eat one, he could possibly be damaged internally or choke and die. So best to keep an eye on the tank to make sure none of the big guys are taking an interest.