Hi,
Well the fish do play a lot of Ax hands overall. A better question is whether he'd shove the turn if he had one or not, I think most of them would so I agree it's fine not to put him on trips too often come the river.
On the river if he has trips he's ahead, if he had 5x/2x chances are he'll show up with a 4 sometimes but he might call our jam with hands like 53/23 (interesting enough if he can't read the board he might actually jam that into us when checked to), he'll certainly call it off if he has 66-99 there somehow, if he has busted clubs he's not calling anything but he might desperation bluff shove when checked to. I think you can go either way as long as you don't fold, there are merits to both shoving and check/calling.
Hope it helps.