At a high level the should_shuffle field in the evergreen task definitions operate under the following logic:

if should_shuffle = true:
  shuffle tests
elif should_shuffle = false:
   if njobs > 1: shuffle tests
else: // should_shuffle not specified
   if njobs > 1: shuffle tests

it would help with clarity as well as for the purposes of our project to have it be the following:

if should_shuffle = true:
   shuffle tests
elif should_shuffle = false:
   don't shuffle
else: // should_shuffle not specified
   if njobs > 1:
     shuffle tests

every instance of should_shuffle: false in the evergreen yml task definitions also has resmoke_jobs_max: 1 and thus, this change should not impact any existing tests.