Always remember that trailers are many times cut in such a way as to hide how things are truly happening. Its entirely possible that Lyse has the upper hand in every fight with Fordola and we are just seeing the parts where she manages to hold her own. Its also possible that Fordola is actually very skilled. Hell for all we know she could be one of Hydaelyn's chosen (and you certainly wouldn't see THAT in one of the trailers).