ZZ.. We have frequently been ADDING stem length to "WSD" bikes to get them to set up properly. Maybe an option for you to get the smaller bike you need AND add a bit of "cockpit" length?

One thing to keep an eye out for with top tube length is that a manufacturer can "cheat" their way to a short top tube on the specs page by making the seat tube angle steeper. This is ineffective b/c we just end up needing to slide the saddle back to get you over the pedals correctly....Negating the shorter tube.