AJJ flop is quite different from A44 or A22. A bad player in particular can absolutely call a 3-bet with a J in his hand, while a 4 or 2 would be at least somewhat unlikely. So this is not like the greatest situation for you in a 3-way pot against two bad players. Given that he lead for this very silly size, I dont hate your line of essentially ignoring it and putting in a real bet myself, but I lean towards taking the pot control line on the flop.
And on the turn, when he lead again, and this time for a substantial size, that is an action, you need to respect. His small flop lead can be all sorts of silly nonsense, but when you raised him on the flop, and he then lead again on the turn, he is showing a lot of strength. The profit at 5NL is not coming from making big hero calls against unknown fish, so I prefer to lay it down on the turn as played, unless you had seen him go on some crazy bluffs in the previous hands.