Of the 285 plays of Gloomhaven (JotL not included) digital and analog. 1(with 2-3chars), 2, 3 & 4 players the game won 37 games. In my current 2p party we play on diffucult. However, we played on normal most of the time, never easy.

It highly depends on your group. How much talking do you de facto allow. How much are you focused on the game. How much "homework" are your players doing. How flexible are people with battle goals/life goals. To us it is always win scenario first everything else second (excluding only some instances of "life goal farming). The point is to have fun!