But the acting wasn't super manly. It wasn't effeminate either, don't get me wrong, but it's like the type of action hero a woman would write. Somewhat sensitive, masculine in a "hearthrob" way and not an intimidating way, etc.

He slams Sarah Connor back into the car and basically sits her down until she's calm enough to listen to him. Then he threatens her.

I would say to watch the movie again but I think the problem is that your idea of true masculinity is largely derived from select pop cultural touchstones so you place too much significance on certain motifs like Michael Biehn being slighter build. Kyle Reese is one of the most manly characters in cinema based on his courage, resourcefulness, integrity, and ability to succeed against all odds.

What I'm getting from this post is that Cameron makes movies for general audiences, not only for men. I don't know if that makes him soy but he definitely sells to women as much as men.

I'm just pointing out that James Cameron was never the most testosterone focused film maker contrary to what gets said.

I had actually never heard that one.