A large branching factor doesn't always give the human the advantage.
When grandmasters play the computer, they often want to trade queens
early, because the computer seems to be better at using the queen
tactically as the boards opens up, while the grandmaster is better in
closed positions where positional play is more important.
A game that is highly positional and has a large branching factor (like
go) does seem to give the computer fits. But I suspect a game that is
very tactical and has a large branching factor gives the computer the
edge. I suspect the progressive variants fall into the latter category.