it is entirely possible if the reloading sustem is developed to reload without removing the entire compartment and the prows would be we could be interchanging load out for the mission requirement the enemy wouldnt know if we have 32 barak-8 with 16 brahmos or 50 barak 8 with 8 brahmos too it would give extensive capabilities and regarding nirbhay i think it would be nasm mr which would be used in ships not nirbhay
Yes, it is possible to have mechanism to remove the compartments on board itself. But I am not sure even Mk41 has that ability for now. Modifying such a big system on the deck is not easy. As far as enemy knowledge is concerned, it is difficult to know how many missile reloads are present onboard even if number of launchers are detected. Also, if one has to anyways do the modification onshore, then the choice would depend on whether it is easier to replace the VLS system as a whole (they are modular & plug and play) or if it is easier to add/remove compartments. I am not sure which option is faster & convenient.
As for NASM, that is indeed a better Antiship missile as it is smaller and more practical than LRLACM. Also, it is unlikely that one would need to fire 1000+km antiship missile in a real scenario. However, my opinion is that for antiship roles, it is pointless to have subsonic cruise missiles when there is no major weight or space constraints. So, Brahmos is enough for antiship roles while LRLACM is for attacking long range land targets just like how USA or Russia launches missiles from its ships. Depending on the mission, one can adjust the number of Brahmos & LRLACM while keeping the SAM missile numbers fixed with a bias towards conservative side as attacks are unpredictable in general.