This far out, I might as well give him the benefit of the doubt and call it a pure tossup. He'll have a very tough race for sure, but I wouldn't call him an outright underdog just yet. Same with Brown.
Though West Virginia is a different story. With or without Manchin, I'm writing off that seat for Democrats.
I think Brown may be toss up, as OH is significantly less R than MT, and Brown has special appeal to WWC, and is a much better candidate than Tester overall. Tester is in a much worse case than Brown.