Pretty sure Cray trotted out all the numbers and the DS all have LOTS of volume . . . in some cases too much really. As for the Argo? Well you have those hab pods, but I usually do not get the 3rd one refurb'd nor do I get the 3rd set of 6 mech cubicles done. Which I grant is b/c I am cheap and exploiting some things in the game I would not in regular BTU- I can only drop 4 mechs, maybe have 4 in a row twice for a total of 8, so why do I need 18 mechs on standby? Heck, first time through the campaign I only kept 10 up in the cubicles.
But for RP in the wider BTU? I go back to modern personnel management and one of the things I read in old WEG's Star Wars Pirate & Privateers. The main privateer in that discusses crew management with a simple agreement that he heats his ship at a higher temperature than the military standard of the Alliance or Empire, and yes he fed his crew better with more fresh food than was typical in military or commercial ships. Unlike the military, his crew were volunteers who signed up and after a cruise if they did not like the conditions they could have gone elsewhere. Better living conditions and food, while having upfront costs paid off in the long run by keeping the crew happy & eager which meant they did not have turnover so he was able to keep his crew as they gained experience. Aside from the hot/cold being reversed- I think William Keith/Ian Douglas Warstrider's normal space heat build up is more accurate for operating ships- it all to me makes sense. Even in the military you can see better commanders make efforts to get their troops better food- either hotter, fresher, or supplemented- when its possible. Making sure the mess section has hot fresh coffee and cold beverages for midnight watches is a good sign compared to walking in the CQ to find old/cold stale coffee in a pot left over from the working day. For field exercises, getting ice when possible out to as many vehicles & crews. Heck, I heard about one battery on base that had something happen to their mess section so the CO & 1SG ordered pizza to be delivered . . . they drove up to the delivery car which had driven out to a empty field to meet the hummer.
So for me, part of my RP'ing as the commander of a merc unit is to provide better living conditions than they might get as part of the regular forces. For example, squad sized rooms rather than platoon bays in long term garrison. Shipping a container that is for R&R- work out equipment (some of which will can be used in micro-g), projector (which can be used in the mech bay on a hatch) which is also useful for briefings, some sports equipment, climbing gear, and others.
Then again, they have two dropships- a Fortress and a Mule convert. The Mule is for support & follow-on (more infantry & armor) forces so it has more quality of life facilities than the Fortress which is a attack ship.
I honestly think when they wrote some of the troop transport fluff, they were watching some of the WWII Pacific movies where the troops were stacked with barely any space . . . and no one thought out the calculations Cray trotted out to project their density for volume.