There's no major issue with strength in the course. Except for dragging a diver out of the water.
The rest, if you're "smart" enough (ie if you get the technique) is done by the gear. Floating on surface, gear removal, dragging someone can be a bit annoying.
I have to admit, during a scenario where we had not 1, not 2, but 3 divers in trouble, it got a bit tricky. But that was mainly endurance and not strength.
edit: I'll just explain that last bit. We were 3 people taking the course, had 2 DMs with us and the instructor. The last 3 were the victims, we had to make a plan to get them. So I noticed the one farthest away struggling to stay on surface, we had nothing to throw, so grabbed a tank and went to her (my rig stays on whatever happens). I came too close to the instructor (which was already being rescued and had a 2m inflated buoy to rest on), and she decided to jump me, at that moment I hadn't clipped on my tank yet and still had to manage my way down to get past her. I ascended only to realise the one I was trying to rescue sank to the bottom, asked the guy on shore where she was, raced down in 1m vis, found her, took her up, did the rest of the drill. It did take me a few minutes to catch my breath at the end of the scenario, because when fighting the instructor off it made my backup reg freeflow, and it went once again when I got to the unconscious diver. So there'd been quite a bit of stress, going up and down, doing things quickly and "neatly". It was all in 3m of water, but it's still exhausting imho.