See Amrhein "Reinforced Masonry Engineering Handbook" for excellent examples of rigid diaphragm analysis with masonry walls, including equations used to calculate lateral deflection of walls. Notice that relative rigidity = inverse of lateral deflection, whether you are dealing with shear wall, or moment frame. Therefore you just need to compute lateral deflection of each shear wall and moment frame for whatever nominal load you choose, say 1000 kips or whatever. You can then use Amrhein procedure, or save yourself some time and use a program such as Enercalc, by coming up with an equivalent wall length/thickness that would result in same lateral deflection for each moment frame.