Surely they should be quite different, with the 'Exact" method giving poorer (but more accurate) results than the simulated method. In any case, they should not produce 100% identical results/numbers across the board.
Are the two methods actually 'live" yet?
Exact method is not implemented yet, so even if you chose it, it will run simulated WF.
We plan to implement also Exact method soon, but we have more urgent priorities.