I think the questions you ask demonstrate that you already understand the issue completely.
You asked the right questions, IMO, and I think they are self evident.
> do they fill the exact same space?
No.
> is Blender adopted by different types of companies?
Yes.
A company or institution that has money to burn will opt for more "professional" suites (Maya, Microsoft, ...). Smaller entities will use the cheaper alternatives (Blender, Linux, ...).