Just throwing this out there, but how better to convince him he's human than to give him human-equivalent strength?
Just an idea.
I like to think that the red eyes are a give away, and are shown in every cut of the movie.
I also like to think that Deckard, an "early thirties" guy who has apparently retired from a career of hunting replicants(Despite his apparent youth), was created just for that job(Roy, Pris, Zora, Leon), and merely "thinks" he's a retired Blade Runner. That any time Replicants show up(That the cops can't deal with themselves), the cops call up Tyrell, and the Tyrell Coproration uncask a new Deckard and pop him on the street opposite the sushi bar to get his marching orders.
I don't mind the idea of him being human, but personally, it makes more sense to me "in universe", that rather than wasting two actual cops, once one goes down, they'd just throw Deckard after Deckard at the problem, lol, till the problem goes away.