Even though i hate his 3bet size im probably just going to call it instead of 4betting because it puts you in a tough spot if he 5bets.
The big problem i see is that if you know you need to bluff shove a scary river to win the pot then you also know that your hand is way behind. With the price he gives you on the river you might as well just call. Even though your hand isnt that strong you are getting like 7:1 and only have to be good like 13% of the time.
This guy displayed to you throughout the hand that he was a fish, min 3b pre 1/3 pot flop bet 1/5 pot turn bet. Fish sometimes have weird mind sets of betting small with really good hands so you don't fold. My advise would be just don't try and read into the fish's bet sizing, just remember that we don't ever bluff fish, we just value bet our good hands.