Hi,
The use of -sc should give you a similar output than trues only, really. I am not sure what causes the issue except maybe if the acquisition duration information are not correctly recovered, this can lead to over/underestimation of scatter as these data are stored as rates (check if the values of the Start time (s) and Duration (s) fields are correct in your datafile header).
In any case, -sc does not provide a proper scatter correction. You can have a look at the following thread for an alternative approach to imitate scatter-corrected data:
Best,
Thibaut