I assume a batsman bats at a very low strike rate. But if he is on the 50 over wicket then some runs will accumulate on the scoreboard but whenever he bats with good strikes but all the team players are out in 40 over then the team score will not be in a healthy position at all. So it is more important for each team to keep their wickets up to 50 overs.
Scoring runs and survival depends on how calm and experienced a team is. Because I have seen a lot of games in the past but many teams perform very badly, they don't perform in ODI matches until full fifty again, they get all out before the 50 overs are completed and the number of runs is very low.
As we mention Bangladesh, they perform well in very few matches, but if we think of Australia, New Zealand, India among these teams, then surely they can score 300 plus runs and keep wickets for a long time till 50 overs.
So basically survival depends on players and being patient is most important. Usually weak teams fail to perform to their full potential in T20 ODIs and Test matches.