There's no inconsistency that I can see.
City's squad sans Agüero is still stronger than ours sans Sánchez.
The difference is that yesterday we argued about injuries to big players in the abstract, and today Agüero's actually done his hamstring. The tree of possibility has been pruned, and all odds have shifted slightly away from City.
As we know over the course of the season it's rather likely the misfortunes will be more evenly balanced.