Assembly is an absolute NIGHTMARE!  Pre drilled holes align, however some of the screws don’t catch for the threaded insert is located too deep.  The only solution was to order 2 inch screws vs 1 34 inch.  Then the area they allotted to bolt them down is minimal (see photo).  Your lucky if you get a 14 turn!  I recommend either paying for assembly or shop around.   If you feel your up for the challenge and have enough beer to calm your nerves, then order early enough to await parts!  Cheers!