Where is this rule from that you need to be level 20 and wisdom 20 in 5e to be an arch druid? Are you comparing it to a monster profile or something? I never saw anything about that.
I hate systems where levels are combined with 'titles'. Well I hate systems that use levels because its incredibly artificial, but that's another topic. I think Larian's approach dealing with levels and backgrounds simply doesn't work in D&D. D&D is not made to completely split background from levels because abilities are tied to it. Nobody cares what level Shepard or Geralt are, the progress is too fluid and kept vague not really being felt in the story. But a powerful druid being level 4-5 just doesn't work... nor a Jaheira with less than level 12 to be fair.
