I typically go with whatever is highest (unless you want things to be more difficult/fragile, and then go with the lowest value you have a level in).
But yes, you'd be correct! Taking a level in a different class can be a nice bump to hits if you want it (though again, this is also a lever you can adjust in your own games to vary difficulty, which I should have explained more fully in the text, just slipped through the cracks). Probably something I'd address more fully if there's ever a revised edition or something.