I don't think Minsc would be origin or companion character. I know there are some datamined files but I believe the idea of Minsc being a companion/origin is abandoned(I have no proof for this, just my hunch).
We will probably see Minsc as a cameo, like we have seen Drizzt in BG1 & 2. He will just kick ass in the purest form a fight or two. Maybe join the party temporarily as Halsin does.
I hope you are right. However, early on Sven said that one of the two companions are written by the same person because of how closely they are tied together. We don't have an insight into the full roster, but from was discovered so far Minsc+Boo would be the only who could fit the discription.
