A P.delhezi's mouth is actually fairly small in relationship to its body considering other bichir if the tetras are deep bodied them should be alright the discus too odds are it might try the cories
while polypterides are predatory they are not overly agressive predators
That said i would look for for smaller more active species than an ornate which are mostly nocturnal good choices would be P.senegalus, and P. polli ( otf mislabeled as P. retropinnis and start a bichir tank -Anne