This is a Shaw Brothers movie that feels very under-appreciated, and I'd say it's certainly better than average within the studio's vast catalog of martial arts movies. However, there are a couple of obstacles when it comes to enjoying All Men Are Brothers. One is that it's a sequel to a film called The Water Margin, which I remember being decent but a bit convoluted. It was also less action-packed than All Men Are Brothers, with the relentlessness here proving almost too much (but not for me; I can watch this classic martial arts stuff all day... I probably would, if I didn't have to pay the bills).
The fast pace and pivot away from a narrative focus means the film can be a bit of a whirlwind when it comes to understanding many plot details, but after a while, you sort of settle into the basics. At that point, the non-stop action is enjoyable, sure, and also made a little more impactful by the stakes that are established hurriedly and sporadically throughout the first act.
It reminded me of John Woo's excellent Last Hurrah For Chivalry, with its level and frequency of violence, but Woo's film had a better story and slightly more creative action. The choreography here is still good, of course, and I loved the frenetic camerawork present in some scenes (made me think of the Battles Without Honor or Humanity series, of all things). Also a bit Woo-esque: the way this indulges in heroic bloodshed, or whatever the martial arts equivalent of that sub-genre is. It's not afraid to hurt or even kill its heroic characters, making sacrifice a theme that shines through by the end, even if the storytelling doesn't do much heavy lifting to make that stuff truly emotional.