I'm gonna do this big write-up on Gamilas Empire's capabilities.
Okay, while everyone's saying how fucked the Gamilas are with the
Yamato having like 10 Mental Models and the Wave Motion Shield, I wouldn't discount the Gamilas. They're an intergalactic empire, and they don't get that far by being stupid or behind the times.
First off if you pay attention to whenever the
Yamato is taking fire, at best, being very generous and charitable, at most probably maybe up to 50% of the shots are anywhere close to hitting the
Yamato on a good day. Simply letting the Gamilas gunners not take lessons at the Imperial Stormtrooper Marksmanship Academy and increase their hit chance makes them a serious threat to even super-beefed-up Fog!
Yamato. In fact I say the Klein Fields and nanomaterials allow more leeway in the amount of damage the
Yamato could take. If it were up to me the
Yamato would take a much heavier punishment during Domel's first ambush on them.
Secondly, you don't see all the Gamilon weapons on their starships being used such as their extra turrets or missiles, mostly due to I assume animation reasons as well as to preserve ammo for the latter. Still, with the threat the Fog!
Yamato poses I'd assume they'd go all-out.
Gamilons use positron beams for their main weaponry, contrasting with the
UN Cosmo Fleet's "amplified light" cannons. These can be either fired in bolts (as we usually see them) or sustained as a cutting beam.
Both of these are showcased in Domel's battle against Gatlantis. I'm not sure how they'd compare to the Fog's photon cannons, but I'd say they're not that far behind. While it's never shown, it can be inferred that these positron beams also have the ability to converge and form a more powerful beam like the
Yamato's positron shock cannons. This can be seen in the 10 minute preview for the Ark of the Stars.
Here, the
Zoelguut-class super dreadnought is shown to fire 3 sets of 4 beams. However in the next shot, only 3 beams (that are noticeably brighter and bigger) are shown. Even in other scenes, where there are only single beams are seen being flung around when all Gamilon turrets are dual-mount or bigger. It makes sense that they have that same ability to combine. (This gives me a funny image of Domel's Zoelguut firing its 12 beams, converging to form 3, then converging again to make one really big beam).
Speaking of the Zoelguut, it could take some pretty nasty punishment. While most other ships are taken out in one shot by the Yamato's shock cannons and missiles, it could keep on going despite being hit by 6 missiles and several shock cannon blasts.
The bow of the ship even outright deflected a converged shock cannon shot. The only other time a shot has been deflected (even the WMS only absorbs, not reflect)
was with the specially-treated magnetic armor coating on the Gamilon Pluto fleet. Even its main cannons are nasty, 10mm bigger than the
Yamato's main guns. I think they'd have comparable damage to the
Yamato's shock cannons.
TL;DR: To up the threat level of the Gamilas you simply need to give them more competence. Their canon technology's already pretty good.
No I didn't just do this so I could rewatch SBY 2199's battles and look at the pretty space ships.