Question on direction for extending Dobot Magician (second development)


#1

I have good understanding of Arduino programming and also c++/python. I need direction (recommendation) on the way to implement the following:

first project: connect to the Dobot arm, say, distance (such as ultrasonic) sensor to have readings for different positions of the arm (i.e. I need to control both arm and sensor at the same time)

second project: control two additional stepper motors, again so that this control in sync with my control of Dobot.

Right now my idea is as follows:

Control Dobot, not directly, but indirectly, through another Arduino board, so that this (second) control board would send commands to Dobot to move and do sensor readings (or stepper control).

I see that there is example of controlling Dobot from another Arduino on downloads.

Now, my question is if this is best method or I can do this without this second Arduino board, and directly connect sensor and steppers to Dobot to control from computer?

Thank you very much for your help in advance.