>>2402198I've seen something with very similar-looking leaves where I am (central NC), and I would guess Asteraceae based on the flowers mine had. I want to say sunflower, i.e. Helianthus, of some kind, but I can't find anything about a sunflower that grows here and has leaves like that.
>>2402274Could be an issue with pollination. Pawpaws supposedly are not self-fertile, so you need at least 2 genetically distinct individuals to cross-pollinate. Pawpaws also propagate clonally, so even if you see 15 trunks, they may all be the same plant, connected by a root system. A patch can take a while to start producing fruit as well, so if the plants are only 5 feet tall they're probably not old enough to fruit.