"Games are too long!" - "Games snowball too easily!"
Pick one boards. When there isn't snowball, games are long and very back and forth(Which I prefer, I'd rather have a 50 minute competition than a 20 minute stomp). When there is snowball games are shorter, either way the boards complain. They are the two alternatives. You cannot have games that are both short and fairly even without reinventing League. Because wins require pushing several towers, inhibitors and a nexus, which you cannot do without an advantage or time.