Size matters not.
The N-1 is a relic by the time of the GCW, even before it's basically a Z-95 with a tuned engine and chrome finish.
A relic? Do we have any reason to suppose they weren't being properly maintained? I don't remember whether they mentioned that in the comics, but I remember they survived while heavily outnumbered by TIEs.
I don't think the age matters if they have been well maintained. I assume the primary attack of the ARCs without title reflects lack of maintenance. If it reflects technological development improving weapon power by fifty percent in twenty years then a hundred years ago their ships must have had basically no weapons at all!



