Why is your second-floor diaphragm connected to only 50% of the shear walls? I assume this is because there is openings near the diaphragm to core interface?. I believe your situation does not create a 'weak story' since all your lateral load-resisting elements are continuous to the ground...
If the columns are sufficiently spaced so that the differential settling of the columns and cores results in a difference of say about span/500, then the impact is minimal. In such cases, depending on the specific situation, further analysis may not be necessary.
In my experience, as mentioned by MilkshakeLake, we size the columns based on the stresses they experience so that they are similar in size. This ensures comparable levels of axial shortening and minimal differential shortening. Another consideration is columns located close to cores. Cores...
