Nah that’s complete underkill. The math I referenced implied 100% efficient drives, so antimatter (or bottled light, both over a dozen times more efficient than a hydrogen bomb) and stated gigatons of fuel per kilo of payload, and armor really just weighs too much for that. If you are willing to coast at top speed for a few millennia, you could use a design like that, but waiting a few millennia with nothing but reactive armor is a horrible idea.
oh yeah 1 trillion percent.
Why wouldn’t we? Think about the scale of a civilization with a dyson sphere. Maybe making ships with gigatons of antimatter using the math I did here would be completely unhinged, but if you colonize the galaxy it stops being crazy, and if you get even a bit more efficient at making antimatter it starts becoming sane. There’s only a half dozen galaxies worth going to, send each one a few ships a century, and you now have colonized every galaxy in range to do anything.