Picking of SU numbers in WM in non-sequential order

Dear WM Experts,

I have implemented WM with SUM. Picking strategy is FIFO with user exit for batch creation date instead of GR date. But facing a problem of picking SUs in a non-sequential order.

e.g.

GR done for 1000KG with 100 SUs of 10KG each numbered 1000000001 through 1000000100 all stored in one bin.

Need to pick 150KG material for dispensing....

While creating TO in Background System should pick 15 SU numbers 1000000001 through 1000000015 as per SU numbers in ascending order.

Here system picks any SU number from 1000000001 to 1000000100, loosing the sequence of SU numbers

Please guide on any standard setup in SPRO

Thanks all in advance