Simple - to save it! It's not mobile. It's fixed!
If the blockade fails and you have to flee, the Mljonirs wil lstay and get destroyed...And they can easily get destroyed with no protection.
That's the whole point. You lose a bunch of Mjolnirs - so what? It's a piece of machinery. It's not, for example, a huge capital ship with thousands of crew. Do you worry about the cost of losing a Watchdog sentry gun? Same principle. Hell, odds on that the principle of developing such a thing would be to save money and resources by not deploying bloody great capships and crew into a combat zone when the enemy you expect (Shivans) have a clear numerical advantage and ability to win any war of attrition. The
whole point of an RBC is that you don't worry about losing it, because you can always manufacture more.
Simply bolting them to a old capship is actually quite plausible. Insted of sending that old Orion to a scrapyard, you just glue 4-5 Mjlonirs to it on preselected spots to effectivly double it's broadside firepower. The Orion can stand guard of the node, and can turn to face the enemy ship should it come out in a different vector (I havn't seen the Mljonirs turn by themselves).
Yeah, because Orions can turn on a pin........odds on if it were caught out, it'd be stripped and struck down before it could re-manouver. And even when
it's moving, the
enemy can move, too! This thing needs to be able to cripple the enemy before they can hit it or, more likely, just jump out. Any time delay, and the blockade is ****ed; it's now defending the node and trying to cover its ass from the ship/s that escaped.
Not to mention that old Orion needs rather a lot of people to crew it. And that you can't just 'glue' Mjolnirs on; I'd wager you'd need a substantial amount of superstructure to reinforce it, prevent heat buildup, etc. And that those Mjolnirs would be pretty much almost as vulnerable as the standalone RBCs, except now they'd have 10,000 people sitting behind them. We can't just magic up these people - or the Orion - out of nowhere, after all (and would they be scrapping an Orion without a superior replacement, unless it was due to crew shortages? I doubt it myself.)
How many people remember a Mjolnir is 93 by 108 by 91m in size? That makes it larger than many freighters (the Poseidon, for example, is about half that size). About, I'd estimate, 40-50% the volume of an Aeolus. That's not a small thing to affix to a ships hull.
And lets not forget; these ships need a lot of people. 10,000 for an operational Orion (and anything less than a fully operation Orion - with - shiny - extra - beams is a liability once it's exposed away from a blockade). That's 10,000 people you'll need to find, for an old mothballed ship.
We know the GTVA uses node blockade tactics that are somewhat vulnerable to a meson warhead (I say somewhat, since the meson blast radius is 3km, and the ships are usually just in beam range).
Technically, they don't. All the blockades I can think of offhand had capships at standoff range, and the players' fighter / bomber wing is deployed from outside of the combat zone.
Second, in all the missinos I played warship allways exited nodes facing the same way. Allways.
And this means what, exactly? That the mission designers laid out the missions on a more or less flat plane with a logical left-right type progression?
We simply don't have an answer for this issue.