Suggest that your Fortress
(?FX-37 @ 21#) would be your THIRD anchor
; behind your Bruce (?44#), and a new Delta
The Maxwell 1200 has maximum 1200# of pull, which may suffice to 20-30kts wind (depending upon current). The 3/8" chain matches your proposed set-up, and could be paired with 5/8" or 3/4" Nylon.