What to choose for automated testing of client-side software?

Question

Software testing

We have: the client part under MS Windows - the user's workplace for placing requests into the system.
Task: to test from 200+ machines with running client software.
Desired result: I want to see errors or brakes that may occur during a large number of calls.
For our part, we have automated robots that, on behalf of clients, put orders to us, but they write directly to the database bypassing the interface of the client part. I want to check the updated software "through the eyes of the user" by setting a certain algorithm of actions.
While the idea is spinning in my head with 200+ virtual machines / containers with some kind of TestComplete from SmartBear, but I am far from practice and this is the first time I have dealt with such a question.
Perhaps there are better solutions with a bunch of different software or a cloud service?