Frig crew amounts being the 2 - 5 has been known for a quite a while. There is chart on these forums that CCP published, go do some archaeology, there's also mortality rates and the like listed on it.
Cramming 5 crew members into a Breacher? I am not operating a slave ship! Replace crew quarters with redundant hydraulics, reactors, capacitors and automation machinery! ALL of them!
If they can fit 5 people into a tank, they can fit 5 into a breacher.
Incidentally, that's how I view most frigates operating: like tanks. Less corridors, more isolated compartments, with one to two specialists per section and inability to move to other sections (or only through very small crawlspaces). Designed for short-duration engagements and not long-term voyages. Depending on how many crew are in a section, one to two foldout bunks with shifts in that section (similar to RL jumbo jets and other big planes) rather than a singular ship crew quarter. No escape pods, there's no room for them, but each compartment is tough and redundant and able to survive a short time separated from the rest of the ship until rescue. And as the assault frigate section says, crew wear exo-suits while onboard.
The interiors of the ships in Star Citizen also offer a good concept of how I could imagine the interior of a frigate being. They did a really good job with those.
