I generally start Horizon Behest at Rank 16, I can get Horizon Leves at Rank 15 so why not? I can still hit things too.

The path I take is 1-11 Black Bush, 12-16 Drybone, 16-25 Horizon, 25-33 Nophica's Well, 33-44 Broken Water, 44-50 lol.