I've had that issue also, though I think mine was 3 & 4, but like you say, in real life, things broke, and sometimes far worse than what the game messes up, and sometimes, there's just no explaining the mess-up...
In the meantime G Man, that shot I have above from TMO / RSRDC, is that what you were after? That is the "default..." Tench boat in that mod, and it only comes that way. You cannot get a single gun on it... I'm still noodling, and CapnScurvy is investigating. I'm sure he'll find what happened. I'm pretty sure the fore- and aft-mount worked previously in FotRSU, though we've never had a dual-mount except on the Narwhal / Nautilus class and some other earlier boats, which come that way in stock...
