Hi,
I also think that it is more important to strengthen the personal relationship directions, then general relationship direction SW and then look for what else could be harmful.
If your brothers sleep in their less good directions (see FS Course level 1) they could attract divorce as well. Check out their kua numbers and help them rearrange their bedrooms/offices (see Essentials course) and place activation cards with their relationship goals.
(By the way, is it their desire to have a relationship or is it yours? Please be careful, you cannot decide for your brothers, it's their life!) I also heard that a mirror on the bathroom door might be a good idea to pretend that the bathroom or toilet does not exit in this direction.
If you have Course level 3, you can also have a look at the flying stars, maybe some negative stars are located on the front door or the bedroom...
Another idea might be to check out their peach blossom direction (you'll find many entries on Google with the appropriate activations or it might just be necessary to remove blocks there). But it should be your brothers' desire to establish a new and lasting relationship, not yours
Love,
Astrid
