You seem to be confusing a number of things here. First of all, I never said Kamille batted the Gaplant away. I said he batted the Baund Doc away, which for some reason you guys featured as some kind of boss that required all the players combined to beat. Baund was piloted by Jerid at the time Kamille swatted him away, and Jerid sucking is a meme but by that point he was a confirmed ace who'd piloted a large variety of mobile suits and had Kamille dead to rights multiple times. There's really nothing to paint the Baund Doc as particularly high performance to the point of making a battle against it require such a combined force.

You bring up the Gaplant's pilot but that was primarily Yazan Gable. He wasn't some kind of inexperienced test pilot, he expertly controlled a machine only usable by cyber newtypes and regularly put the protagonists to task. He came out of Gryps with the highest named character killcount. Side stories such as Return of Johnny Ridden place him in slightly tuned up GM IIIs and Jegans putting up an even fight against extremely high performance one of a kind machines controlled by skilled pilots. The other Gaplant pilot, Rosamia Badam, was a cyber newtype managing a machine only the very best and toughest regular humans could control.

I say this mostly to establish that, to me, not only does it look like you haven't read my post too well but it also looks like you're trying to argue a point you don't actually have. I'm not sure how height (head height is what matters to help define center of mass, max height is taller because it literally has pointed thrusters sticking out the frame), weight and all these stats matter when they absolutely never impact how the MS perform ever. Did you know Byarlant Custom has a less powerful generator than a Jegan? Or that Rick Doms are supposedly worse at maneuvering than GMs? Even though everything points to that not being the case?

Not to mention that being lighter would be advantageous for the Zeta, considering it's primarily centered around high speed and maneuverability. But anyway. Zeta Gundam almost literally helped define the era for MS development. The Federation spent the next decade trying to trim it down for feasible mass production because its performance was so good it gave Neo Zeon's insanely advanced technology hell when piloted by a bunch of kids almost literally picked off the street. It has a space magic device, a high power beam rifle it can use to attack from good distances as a high mobility unit and its beam launcher is meant to oneshot ships.

You keep taking the term "mobile armor" to mean some unstoppable machine when by this point, it just means "mobile weapon not a mobile suit". Mobile armors are used as super powerful boss units because having a large inhumanoid (later, sometimes humanoid) machine makes for a quick visual identifier. This thing is different, it looks mean, it's dangerous. But by now, there's a myriad of transforming MS whose plane form is called "mobile armor" and that doesn't make their performance magically overwhelming. Saviour, Abyss, Chaos, the mass produced Murasames all call their tranformation a "mobile armor".

Are you telling me this is all seriously brought about because you two see "mobile armor" and instantly think a Big Zam-tier battlefield clearer despite everything pointing to that not being the case? As for the weapons, Gundam has had beam shotgun-type stuff ever since the GM rolled off the assembly line with a cheapened beam rifle. That's what a beam spraygun is. A weapon that fires diffuse beams, which isn't great when any stray shot from a distance can ruin your day and yours don't reach the target. As for the missiles, please, when have they ever really amounted to much more than cool visual flair.