while there are some caveats to the following, most longbows fall into 3 camps for bow length versus draw length. imo, these are the minimums and longer is always better for smoothness of draw, lack of stacking, and lowered string finger pinch, but up to a point where length compromises efficiency.
hill style american flat longbows with backset, straight or string follow - very low to low brace heights ...
64"/26", 66"/27", 68"/28", 70"/29"-30", 72"/30"-31"
mild r/d longbows that brace to a "D" shape - low brace heights ...
60"/26"-27", 62"/27"-28", 64"/28"-29", 66"/29"-30", 68"/30"-31"
aggressive r/d longbows that show tip reflex when braced - high braced heights ...
56"/26"-28", 58"/27"-29", 60"/28"-29", 62"/29"-30", 64"/30"-31"
my draw length is 29". some of my longbows ...
58" 50# bamabows expedition t/d (aggressive r/d)
60" 50# thunderstick moab (aggressive r/d)
66" 55# mohawk t/d (mild r/d)
70" 54# craig hill tembo (string follow american flat longbow)