Change the order between control stimulus and comparison stimulus

I am planning an experiment in which control stimulus and a comparison stimulus are presented. I want to change order between Change the order between control stimulus and comparison stimulus.
the control stimulus speed is fixed, but the comparison stimulus speed is changed in 7 steps. I created separate routines for the former and latter because the latter had different finishing times.
The final goal is to have two routines randomly presented in each trial.

I found a way to make each block run randomly, but I couldn’t solve this problem.

thank you.