yeah, you're missing out on important, older skyscrapers outside of chicago like power and light (476 ft) and fidelity national trust (470 ft) in kansas city and of course the stuff in detroit like the book tower (also 476 ft) that would add an element of interest to the graphic and highlight the presence of the deco tower boom in the rest of the midwest.
wikipedia.com
maybe even lower to catch the pre-war skyscraper-like buildings like the continental tower in midtown st. louis (not for chicago).
wikipedia.com