Yes, it is overstocked (the fish are not yet at their mature sizes so it may not seem like many) but more importantly it is incorrectly stocked.
Colin mentioned the barbs...this species needs a group of ten minimum, and a minimum 30 gallon tank for that group, on their own (substrate fish are OK but no other upper fish). Otherwise, they may get very nasty to each other and other species.
Angelfish need larger quarters, but here we come to another issue. Two angelfish rarely get along for long, unless they are a bonded pair. Two females might manage, sometimes; two males never.
Keyhole cichlids are one of the most peaceful species of cichlid, so they may work out, but the barbs are going to be an issue for these too. Same for the Bolivian Rams. And with both the keyhole and Bolivian, two fish is hit and miss, same as for the angelfish.
