There are some "tactics" to deal with Hideout defences and I personally enjoy every attack. Unlike some RNG city maps, or Ship from TFTD where it's a chore to sweep and not lose your gals, becouse enemy can be "patroling" every room and stay there forever.
My most successfull tactic is to just place barracs/burrows next to Hangar/Hangars and elevator while keeping empty space between anything else.
I don't think it's that unusuall.
Keep few dogs to send them into tunnels, then place gals in the hallways leading to hangar. Those will snipe anything coming out. Keep few Shotgun/melee gals around the corridors. Send "harass" parties by maintenance tunnels above.
Something changed during the last update? Academy sends Ambulance with proper weapons, dark ones comes with UAC weaponry and ratmen/bandits go with various crap guns.
Even if there are some untypical guns, it can be explained by the fact that they took the initiative, they geared up for this assault a bit, since it's not their normal job.