I didn't want to partake in this discussion but I felt many were being unfair to Benjamin. He was doing what any good friend would do, going to your help your friends when knowing they had been pushed into a difficult, potentially fatal, situation.
Regardless of how strong one is, that does not mean one does not need extra help. Indeed Astina did think and ask for his help, just in a different capacity. Moreover he backed off when he realized she was totally capable, and told her he trusted her.
Imagine your best friend is forced to go fight a rumored mafia boss. No matter if your friend is the MMA champion, would you think it's right to let your friend go at it alone or would you run there to help in any way you can?
The mentality that strong people don't need help is quite unhealthy. It forces the strong to always be strong no matter the situation, and to take care of things by themselves. It isolates them, and can make one feel lonely, voluntarily or not. I'm of the opinion that everyone needs help, big or small, at some point, even if they don't explicitly ask.
Back to the story, I have a feeling people are more peeved because Benjamin is a guy, and we as readers saw how she tamed the beast easily. But put yourself in his shoes, all he knows is the Duke is a bloodthirsty beast, and his friend has been forced to marry that beast. You're telling me you as a friend would just shrug and say hey she could handle it, and just go about your day as usual? It's not like she said she needed help or not. I perceive that as being cold and uncaring.
I suspect the stance of strong women needing no man's help plays a role in these complaints. That's a toxic mentality, much like toxic masculinity.
Phew, now that I got it off my chest I can go back to enjoying the series now. Benjamin is a good and respectful friend and man, so far.