That doesn't even begin to make sense...
Servant Rankings aren't as "pointless" as he makes them out to be(The problem is that Nasu implied but only truly stated that not all Servant Saint Graphs are created equal and thus, Cursed Arm Hassan's Saint Graph is not the same as Sanzang's nor is Artoria's Saint Graph the same as Jason's) but to pretend that Servant stats and rankings don't matter to the point they can flippantly change not just between Classes but literally between having a Swimsuit or not is asinine to the nth degree.
Servants literally tweak their Spirit Origins to switch different Classes as we know in FGO but that doesn't fully change what they have access to.
EDIT: Hell, what completely annihilates Alkamus's argument? That Musashi in Samurai Remnant's moveset explicitly uses both of her abilities in both Saber AND Berserker movesets explicitly from FGO itself. Don't believe me? Go and look at her moveset in Samurai Remnant and go look at her Animations in FGO, there is virtually NO DIFFERENCE.
Ah yes, Rho Aias, the Shield that blocked Durandiana that was able to block Lostbelt Artemis' Planet Destroying Laser...
Even if degraded one Rank below like Archer's would still be more than enough to offset enough of Excalibur Morgan that Belleophron can take her.
Secondly, Alakmus is doing insane gymnastics to prove that "Nasu stuff makes no sense" but intentionally removing context from all of that as for one that "Meteor" even acting outside of Moriarty's plot was going to destroy the entire Singularity and the Earth itself:
Final Tally Model 1 Bennu Yield Range (based on Chixulub Impact something or other) = 310.707 teratons to 1.386 petatons Bennu Speed (02/01/1999) = 1,755,281,683 m/s Model 2 Bennu Yield (09/11/1999) = 28.8 petatons Bennu Yield (09/22/1999) =...
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Gae Bolg was also stated by EMIYA himself to be on the level of Gungnir, if not higher than that(Which is why it's so damn strong considering how legendary it is under Cu to the point it's Strike is virtually an Authority despite Cu not being a Divine Spirit):
vs Rho Aias and finally, Belleophron is stated to be the 2nd strongest Noble Phantasm even in comparison to thrown Gae Bolg:
So none of these comparison's work if you, I don't know, read the story or did some research. There has been a constant reason why everyone states the Fifth Holy Grail War was bullshit stacked with powerful Servants... because it WAS.
Trying to tie feats in that they look "less impressive than they are" doesn't even work for Fate because even looking at them in the fashion Nasu wants you to do so would easily get you Continental and above and Relativistic real goddamned fast even in F/SN's VN, let alone the Anime.