As an actual character, I assume Batty would have been mass produced. Combat model - optimum self sufficiency.
Scott also wanted to cast Rutger Hauer as Mr. Weyland at one point. Can you imagine the mess all this would have created?
Valaquen wrote a great article a few years back about all that. Even had concept art of Batty and Rutger as Weyland IIRC. If Val reads this maybe he could drop us a link?
Blade Runner is set in the 1940's as much as it is set in the future. Stylistically completely different from the Alien universe.