What I can suggest is to create a function that will receive the validators and return a combination of the messages that they display. I've created an example to showcase how this can be achieved, enter 'test' to see how both validation messages appear:
If you would like to have this as a feature, you can submit a feature request here. We can also do that for you if you prefer us to do it. The feature will be planned based on community interest.
Hope this is helpful.