SE will never have to release new jug pets again, because we could pick from the existing families and adjust stats accordingly. Some folks might say that is getting too close into PUP territory, but it's better than SE adding jug pets randomly (or never).
Making a system this free would likely be a balance nightmare. But I would probably have to agree that if we went back to when beastmaster was designed, it would have been a much better system.
These pets are at 119. What's an ML50 beastmaster to do at that point?
If jug pets are not influenced by master level, than that is something that really needs to be addressed, as all other pets improve with master level.