play some t20 cricket. Change the mindset of the batsman for those evening games and hopefully it will filter through to the longer form of the game.
Putting my batter hat on, most batsman play what is in front of them. If you have won with low scores twice then it says to me the wicket wasn't great and the batsman played accordingly. Likewise they nearly chased 244, so it strikes me they are doing a decent job.
Batsman can always be more positive, take calculated risks and look for quick singles but when that trade off results in wickets thrown away, then you need to re-think the personnel. Maybe move your more passive batsman down the order and bring some better strikers up the order. I worked on having 2 steady batters and 4 shot makers in the top 6. One steady opener and possibly your number 6 to safe guard against collapse.