I am not sure I follow this? The torque will increase by the ratio of reduction, e.g. for 2:1 your torque will double, even if you lose 10% in efficiency, your torque has increased to almost double, besides that your load to motor inertia ratio will will be reduced by the square of the reduction, for 2:1 this will be reduced by 4.
The industry recommended target for this is 10:1 or less.
Al.