The #2 method is the best way to do it, and it should NOT cause a CTD... in any mod set... If you had a "gun fix" kind of thing, I might be suspicious of that, but you don't... I would be tempted to re-order your mod list, though I doubt it would help:
A_RFB_2.0
B_RFB_2.0_Patch_23April2010
C_RFB_2.0_Patch_06June2019
D_RFB_Corrections (?? - check it first)
E_RSRDC_RFB_V575
F_RSRDC Patch (not necessary - traffic fix)
G_OTC RFB 2.0
H_Increased binoculars for RFB OTC
I_U.S. Medals Fix II_RFBv1.52 (might conflict with OTC's Medals)
J_OTC_Gato Sonar Bearing Fix
K_SMMO for RFB 2.0
L_Clean and Quiet Map (does it conflict with the above??)
M_Stop The Shouting
N_RFB_LocNames
O_Webster's 300' Underwater Visability for v1.5
P_3000 Yard Bearing Tool (1920x)
Not that a re-ordering would help the deck gun aiming, but you should get a more-accurate mix of the mods.
Have you done any Save folder editing to the deck guns?
