Karna... is a little much if we include Vasavi Shakti.
Brahmastra Kundula does make more sense as you stated but again, we do have powerlevels on that similar level with alot of Servants so it would make him strong(Especially if somehow he was adapted to Turas Realta or another series that would make the destruction plain to see) but it's nothing close to "Machine-God" level which is a little much considering those are Interstellar Battleships of various ludicrous levels of power respectively.
And yeah, none of those shots was True Name Release and he has a massive energy supply to spam them like he does(Especially with them ignoring Space-Time) so if they was a TNR, then yeah, that would present a big problem.