Hard to answer. Further than you could with 2 miners and a hauler?.. 
But seriously, there are lots of variables here:
- When you say “industry”, do you mean building and selling items, or just mining?
- Where will you be mining?
- Do you have plans for adding science and production skills?
- Where will you be building and selling things?
- Do you have access to things like moons?
- PI?
- Will you be doing your own reactions, invention?
I guess the short answer is that you can get a bunch of ore with that kind of setup (2 exhumers, 1 Orca/Rorq, 1 hauler), but anything beyond that is up to what you are trying/wanting to do.
It goes without saying that all of these accounts will have to be Omega, of course.