My thought on the matter is that it is kind of nice to have the ship table data be baselined to something reasonable before fredding ship's actions in the mission. Yes, I could make the raynor kick everything's A** all day long with only 10,000 hp by setting armor values and smart guardian of systems in fred for every mission through an entire campaign, but It would be kind of nice to have believable stats in the tables that only require tweaks. In the case of the Raynors, it seems like they should have maybe 300,000-400,000 hp or so in the stat blocks, and then you can go in and fiddle from there. Sure that is basically the same thing as Heavy Armor 30 or so, and if you would rather do it that way, then just set the default to heavy armor 30 in the table. Otherwise the future fredder using the model has to go in and try to figure out why the ship described as a brawler keeps blowing up like a glass cannon, and script it to behave as intended every single time.
Unless of course the Raynor is intended to not be used in any other mods than the official blue planet campaigns. Then we really have no right to be looking at the tables or thinking about how it would act in other situations than the ones it has been scripted into, since its IP would be off the table for anybody else.
On a side note, I have no problem with the Atreus leaving after getting shot at by two Narayanas. I think it would be silly to hang around to see if the UEF deploys an Occulus and a Solaris or two, and maybe some Durgas to target your engines. Jumping in, taking a shot and something vunerable, and jumping right back out seems like a good strategy to take initiative from your enemies. I figure Steele would do that as much as possible.