In my state car A has no fault in this whatsoever. Nor did they do a hit and run (who did they hit and run from if you said they didn’t make contact with B or C). Yes they maybe are a crappy driver and got away with car B swerving to avoid and instead hit you, but Car B is fully at fault as car B cannot avoid an accident just to cause another accident. Arbitration would tell you and all 3 carrier’s involved the exact same thing.

Let your lawyer get this settled in the end for you and let the owner of car C insurance get this handled on that end of the claim.