Test matches now are bat first and win. With doctored pitches globally, winners are decided at the toss most of times. Anything above 350 will be a winning score. Sam Curran and Marsh both are in, England needs to be really messed up to let this away.
England player should not think about the score bat for time. You bat at least two days for the first innings of a test match and you make at least 400 runs. That way you will at least make it so you shouldn't lose the match if you bowl and field well. This is something that England has consistently failed to do.