single large texture (1024x256)
...That's not a large texture...
But I would try to UV-map it one single texture [keeping the parts scale/resolution identical] if possible. If there's repeating detail it might be good to do additional textures. But there rarely is, even subs don't have repeating textures if you aim for full realism. Of course left and right sides are often mirror images so you can save some UV/texture work there. And you will need additional textures for sure, like for emblems, flags and such...
Max practical size for a game texture IMO is 2048*2048 because it's quite well supported these days and Blitz scales it down for ancient crap which supports only 1024*1024 maps.