Firstly,
What are you trying to say here?
I was, though unstructuredly, trying to say that all these arguments were on the fluffy FS standards, which, like many sci-fi games tend to violate the rules of realism.
Secondly...
The Orion is as it is. Great-War era design. The GTVA didn't bother much to improve its AA armament to newer standards. That's as far as canon can get.
The Hecate, is as it is. It's a cross between carrier and battleship, as most of us look at it, but I believe it handles better as a carrier.
Umm. You don't get the point. The Orion, from a basic design POV, is a very good, highly defendable ship design. Its turrets are placed for optimal coverage, and it has very little in the way of true blind spots. Could its AAA armament be better? Of course.
Yes, I'd agree, it's highly defendable and all: but will it last long against Shivan destroyers? And bombers (without the goddamn Alpha 1 in action)?
The Hecate, on the other hand, with its weird design, is easier to take down because it can't defend itself well, and because its design make it harder for its escort fighters to fight around her. In addition, her anticap firepower is pityful, and easily taken down.
You could say that its anticap weaponry is pitiful, but it isn't designed for that, as I see it. It's designed to operate on search-and-destroy missions, were it wouldn't engage direct combat, but rather, deploy bombers to crush its enemies. Look back at "Slaying Ravana".
Take all of that together, and ask yourself which ship you'd rather fly off of.
I wouldn't fly off an Orion against a Demon.
An Orion, which needs some extra escorts to shoot down bombers and bombs, but can take care of most of the big stuff easily, or a Hecate, which needs protection from bombers on their way to this blind spot or that, AND other big ships at the same time?
Actually, this wouldn't be the case when handling Shivan destroyers. Basically I would rather send an elite bomber wing with fighter escort than an Orion with fighter escort to take them down. I wouldn't want to risk losing an entire flagship to some mission.
Also, I think I'm realizing that you're relying on big ships to handle big ships. Well, no. Especially against Shivans, who, apparently, have less dangerous anti-fighter/bomber armament than their GTVA counterparts. However, they handle big ships tragically with their LRed, which is far more efficient than the BGreen or the sucky TerSlash.
Would you rather send bombers and fighter escort against a Shivan destroyer, or an Orion with fighter escort (or even bomber escort) against a Shivan destroyer? Would you want to have the risk of losing a wing of bombers, or losing a destroyer? That's basically my point.