Well, the simple geometric analysis depends on knowing the azimuths and roof pitches fairly exactly. I'm going to assume you mean 0 degrees azimuth = due north. So 211 degrees is SSW, and 136 degrees (a 75 degree difference, not 90?) is SE.
If your roof pitch is 4:12 (a total guess), then that's an angle of arctan(4/12) = 18.4 degrees. You can represent each array by a vector, whose direction is normal to the array and whose magnitude is the number of panels (if they are all identical).
Then array 1 is 7 * (sin 18.4 * cos (90 - 211), sin 18.4 * sin (90 - 211), cos 18.4) = ( -1.14, -1.89, 6.64). And array 2 is 23 * (sin 18.4 * cos (90- 136), sin 18.4 * sin (90 - 136), cos 18.4) = (5.04, -5.22, 21.82). The bit about "90 - azimuth" changes from the compass convention to the math convention where E = 0 degrees, N = 90 degrees, etc.
So when both arrays are illuminated, they will jointly act like an array represented by the sum of those vectors, or (3.90, -7.11, 28.46). That vector represents an array of 29.6 panels (the norm of the vector, sqrt(x^2 + y^2 + z^2) ) at an elevation angle of arccos(28.46/29.6) = 15.9 degrees and an azimuth of 90 - arctan(-7.11/3.9) = 151 degrees
Now you plug your location into PVWatts and model an array of size 12 kW * (29.6/30) with those parameters, with the different DC/AC ratios from a single 7.6 kW inverter, or a 11.4 kW of inverter, to see what the difference is. Except you need to confirm the azimuths and roof pitch, and adjust my computation accordingly.
Cheers, Wayne
[I went through the computations because I haven't actually done it before. I'm slightly surprised that for a roof pitch of 4:12 and an azimuth difference of 75 degrees, the equivalent array is still of size 29.6 panels. I did double check the computations, but there could still be an error.]