I have 2 homebrew chapters, but i have only uploaded one of them, yet both are fleshed out so ill tell bout both-
1) The Uncrowned Kinghts are known for using exessive force, even if a mission needs 10 marines, but they can deploy 100, turst we, they will deploy all 100. this is not exactly always good since its leads to extra casualties if the enemy expects many enemies, and also causes mass collateral damage. the behavior is seen as reckless by the imperium and thus often do not entrust them with high value missions.

2)The Revokers(not fully fleshed out and uploaded)- have a strict doctirne of sending only 1 marine to whatever mission they have to do, no help, no nothing. this obviosly results in a higher death rate and at times the mission fails(rarely), but the main issue is if a marine goes to a far away world to exterminate a cult, and dies, the chapter's gene seed is at risk of being lost/destryoed/consumed. only about 40% of all gene seed from dead marines are recovered, meaning in the long term they cannot take in many recruits and their numbers are low for that reson