Why not meet halfway and just replace the fob sentries with two playable omni sentries that a Bravo comtech/sl can place as they go around the fob and cade, it should ward off the lowpop xenos while not negating high pop swarms meaning bravo has to still be Bravo. If people take them to the front? Well the FOB is going to be completely on its own then. Could even make them battery powered if you are worried about people using them on the front line so after 20 minutes of being deployed they fizzle out.
Limited low pop protection while not impacting high pop too much where there is the actual pop to make the marine side actually function as people are playing the slots needed. Xenos should still be able to swarm it if they are dedicated to the push.
Added bonus is that someone could actually make use of the sentry laptop because no ones taking it for their single sentry and no one else has a sentry because Brute exists or they’re protective of their comrade sentry.