Really, I think you can have structure and off the cuff. Tomkins is fairly off the cuff and we have done so good stuff too.
I don't think there are any absolutes in sport and as soon as you think you have discovered a winning formula that's when other teams go by you by rethinking the wheel.
Sometimes it's big players that are the fancy of the day, other times speed, other times a mobile pack. Some times it's ball handlers other times it having a kicking machine that help.
Some would say defence is the key at the moment, but it will only be a matter of time when an attacking side rules the day as when all defences come to a standard it takes the team that can attack to make the difference and as soon as everyone latches onto that, defence will be king again.