Their personalities are highly individual. Some are shy and withdrawn, some are pushy and dominant. I have four large H. coryphaenoides spread among several 6' tanks. Two of them are very shy and very rarely leave their staked territory except to eat. The one in my 150g living room display pushes around 11" Heros severus and doesn't tolerate anything nearby. H. temporalis are similar.
I've found that all large cichlids (Uaru, Heros, Hypselecara, Hoplarchus, etc.) will snack on small tetras if they feel so inclined. Most Hypselecara probably wouldn't bother them if they're well-fed but I'd never say never. Even Uaru, which are thought to be passive for large fish and heavily herbivorous-leaning, slowly pruned down schools of long-finned serpae tetras and lemon tetras.
My suggestion would be to add the smaller species you plan to keep first, then add small chocolates and allow them to grow up around the smaller established tankmates. I would also be careful only selecting two of any type of cichlid, as most unpaired SA cichlids will end up with a dynamic where a dominant fish bullies and harasses the other. I always recommend getting a group of them to raise out together to spread the conspecific aggression around more evenly, and then as they grow and pair, thin their numbers by rehoming or moving the rest. Or just keep them as singles, which has sometimes worked well for me when it comes to temporalis. There is a reason my four H. coryphaenoides are now all residing in separate tanks... they weren't until a couple months ago when one decided to mutilate all the rest.