yeah pictus should be able to hold their own as long as they aren't too much smaller, i have a grown pictus in my tank now with no problems but when i tried adding 2 more smaller ones they picked on them and bullied them killing one and making me move the other one into a smaller grow out tank, so im not going to put him (or the new one i purchased) back in until they has grown a bit. as for other cichlids to add, in that size tank i would only go with maybe one more med sized cichlid like a carpintis, severum or something else along those lines of size and aggression
Loves Severums why would he need to upgrade? a 75g is 18in wide so is plenty big enough for a 10in fish