I'm all for the toggle. Or at least if they make it so that mentor matches have solo-medium-and-below-level difficulties, without an antagonist...
You dont know how many times I went into a mentor match, just to face high difficulty and an antagonist.

Ok. Thank you.
Btw, how many points would you put into it?

But the characters like genebra cost way too much...
If you think about it like this, genebra is obtainable by level 36, but her cost is so high that you could be level 56, and still not have her. 
I mean, unless you haven't bought a single weapon or character,  (including Shane) except maybe hans...