The clock/gate question wasn't doubting your set-up. I just wanted to be sure you had some thoughts on where the clock/gate/trigger was coming from.
Clocks work great, but only for rhythms that are constant division (16th notes, 8th notes, etc.).
In the case of your Euclidian module. The clock goes in the clock input and then the output of the Euclidian to the Mimetic. Then you can set your ratios as well as your starting point and the Mimetic will follow the Euclidian module.
You will also want a reset from the Beatstep Pro to both modules. It can be something as simple as a 16th note played every measure, every 2 measures, every four, etc. The reset will make sure that the Euclid and Mimetic always start in the same place and reset so your pattern is consistent and stays that way.