Probably because battles occur at much closer distance. 1 sector is already an interplanetary distance. Like from Earth to Mars. Battles on the other hand, scaled to something like between Earth and Moon. No wonder you can get better readings, scattering armor or not ! As to receiving designs when you lose, why should it matter ? Your ships send continiuos telemetry back to HW by (subspace?)radio or laser. You don't really need hardcopies
