A37575
You are correct in theory but full go around thrust on the B738 gives a very large pitch up and is an excessive amount of power at light weights.
The chances are that if you push the throttles to the stops while selecting flap 15 and then get select the gear up you will have built up so much inertia in the aircraft that you will fly past a 1500 ft missed approach altitude, one click on the TOGA button gives a reduced GA power that makes the whole thing more manageable, two clicks will give you full GA thrust if you should want it.