What it seems to me you are adjusting is the "poundage" (strength?) of each limb to achieve a balance, so that each limb is applying the same force.
The forces applied by the limbs push to separate the axels and in a static condition are precisely equal or "balanced". Even if you were to crank one limb completely down and have the other backed off as much as possible, the forces applied by each limb would be equal. If those opposing forces are not equal therewould necessarily bemovement until the systemreturns to a balanced condition. The angle of the string relative to the riser of course changes as you make these adjustments as well as where the point of maximum leverage occurs. Ideally, as the bow is drawn and of course shot the amount of compressing and decompressing of the limbs in terms of distance moved will be equal but mismatches in the stiffness of the limbs canresult in problems. If for example the bottom limb is much softer than the top, then it will bend much morebut again, thetotal force exerted by the top and bottom limb will beequal. It's just that a stiffer limb moves less to exert an equal force.