After more than half a year into the hobby and bouncing between several different armies, I've finally decided I'm going to collect and play the Angels of Defiance space marine chapter. As part of this, I want to expand the lore of the chapter with my own homebrew since all GW has given as canon for the chapter is a colour scheme and a few other bits of info. For now this is what I have:

As successors of the Dark Angels, the Angels of Defiance are among the Unforgiven and have an inner circle composed of the highest-ranking marines who are cursed with knowledge of the Fallen and a duty to find and bring them to justice. However, a rift amongst the inner circle has begun to form.

During the Nachmund Rift War, only more than half of the first company were able to make it to the system at the request of the faltering Castellans of the Rift Space Marine Chapter due to the chaos caused by the Great Rift. In their time fighting, the demi-company formed a bond of brotherhood with the other scattered chapters that were present, forming the Wardens of the Gauntlet. At the same time, the majority of the rest of the Angels Defiance returned to Caliban at the request of the Dark Angels to defend it against Typhus and in doing so gained a deeper respect and comradery with their progenitors.

After the conclusion of both battles, the chapter reunited, and all was well for a time. That is until their sacred duty to find the Fallen and return them to the Rock arises once again at the request of the Dark Angels. Members of the inner circle who joined the Wardens of the Gauntlet feel that pursuing the Fallen will only take away from their duties elsewhere, especially valuing the oaths they made to the Wardens (as most of the inner circle is comprised of the first company, they are not a small minority). Members of the inner circle, including the Chapter Master, who fought alongside the Dark Angels are as dogmatic in the hunt as all of the Unforgiven and refuse to entertain any talk of treachery.

Unbeknownst to them, the Fallen they capture are often fraternized with by some members of the inner circle, who have begun to feel sympathetic to the Fallen's plight. For now, the Chapter operates smoothly, but it is rumored that operations to interfere with the Fallen's capture are being taken by dissenting members of the Angels of Defiance. Who knows what the future holds for this young, troubled chapter.

What I'm mainly looking for is whether or not this kind of inner-chapter conflict is even possible. Thanks for any help!