My primary point was that CNN did a poor job of informing people with that article and I provided an example to show why. I like your initial conditions, too. Let's see what it means in terms of NYC (20% with antibodies) and AZ (3.1% with antibodies) and use 2.5, the midpoint of your R0.
From inverse.com
Incubation period: 4-6 days for most to develop symptoms
Infectious period: 1-3 days prior to developing symptoms and for 7 days after developing symptoms.
So, most are infectious from 1-5 days after being infected and continues until day 11-13. 8 days is about in the middle, although I'd argue it's more likely people infect others earlier in the infectious period before they show symptoms as they are less likely to isolate themselves without symptoms.
As the coronavirus pandemic stretches on, a small proportion of Australians infected have now died, while most have either recovered, or are likely to recover over the next few weeks.
www.inverse.com
So, we go through a generation of the virus in about 8 days. With R0 = 2.5, the effective R for
NYC: 2.0 = 2.5*0.8
AZ: 2.4225 = 2.5*0.969
- after 8 days
NY: 2 people
AZ: 2.4225 people
21% higher rate of infection in AZ
- after 16 days
NY: 4 = 2*2
AZ: 5.8685 = 2.4225*2.4225
47% higher rate of infection in AZ
- after 24 days
NY: 8 = 2*4
AZ: 14.2 = 2.4225*5.8685
78% higher in AZ
- after 32 days
NY: 16
AZ = 34.4 = 2.4225^2*58.685
115% higher in AZ
While both are in ugly exponential growth territory, there can be little doubt that NYC isn't in nearly as bad as shape as AZ simply due to the number already infected in NYC. Yes, NYC may be doing other things - quite possibly things that AZ is not doing. However, they get the above "advantage" over AZ in terms of new growth without doing anything other than a poor job of containing the virus in March.