Su Xin has always disliked forcing others, and it's no different now.
Whether these people are willing to train at the Six Gates as he has suggested is ultimately their choice and not Su Xin's concern. After all, he has never tolerated incompetence among his subordinates.
As for their affiliation with the Su Family, Su Xin doesn't care much.
Although he's currently the head of the Su Family, Su Xin regards it as nothing more than a convenient tool.
He certainly isn't foolish enough to risk his life for the family like the Great Ancestor of the Su Family once did.
To him, these Su Family members are just like his other subordinates; competency will earn his attention and nurturing, while incompetence garners no resources or care from him.
Whether they're from the Su Family or share his bloodline is of no significance.
The countless disciples of the Su Family pondered, and eventually, they all made a choice.