My understanding is a bit different, although I am not making any claim to the truth.
I will not make a nice figure like your but my understanding is this:
There are 3 compunds being tested, which translates into 6 arms in the study. This js because for every compund there is a control arm which uses hiltonol instead of fimaporfin/fimaVacc. However the control arms have only 1 cohort each because there is no dosing to consider.
In the fimaVacc arms there are more than one cohort per compund because they had to find the right dose. If they used 5 different doses, then we woukd have 3 x 5 x 6 (assuming 6 pasients pr cohort). Pluss 3 x 6 for control.
This adds up to 108 but maybe they narrowed the dosing a bit using the first compound…
Anyway, this is all just speculation to pass the time until we get some results…