Assuming he has no draws seems extremely silly simply based on the fact he's 40/4 preflop over a tiny sample. There are plenty of players with stats like this who are more aggro preflop with good draws. The min donk here is also defo more indicative of draws than made hands, idk why people aren't picking up on this. How often do you see fish donk small with nut hands vs with fds etc. I don't think giving him only nfds would be unreasonable at all given how many other draws this guy could potentially have in his range. Against only better hands, AQ and nfds alone we have 34% and that accounts for no random spazz from other draws/worse top pair from a likely bad player we have no read on whatsoever post flop who's just taken a line that fish take fairly commonly with a draw on a board where a wide limping range will contain every draw under the sun.

Yes we should be folding lots to passive players postflop when they shovel money in, but honestly we don't even know how passive this guy is over 20 hands. Fish are bad, dumb and should be assigned at least some sort of a spazz factor in a lot of spots until shown to be really passive postflop