If you are dealing with a dysfunctional family relationship, there is going to be some misunderstandings along the way. Dysfunctional relationships do better with proper documentation. You may have a hard time communicating with dysfunctional family members, but the written word is much harder to refute than a game of he-said, she-said. In fact, the more specific the documentation you have, the better. And a document has the added benefit of allowing people to consider what is being proposed at their own speed, on their own time, and in their own way. We all take in information in a different fashion after all.
Many parents make the mistake of not documenting their thoughts and plans in the first place. If you have children that do not get along, do yourself (and your children) a favor and document what you want. Whatever you do, do NOT make one of your children the Trustee. Even if that one child is the most honest person in the world, the fact that they are one of your children is enough to create a potential fight.
Might I propose naming a neutral third party as Trustee. Preferably a corporate Trustee or a private, professional Trustee. Or at least provide a mechanism that allows a neutral third party to take over in the event there is a fight among the children.
All this is to say that the better you document your desires and wishes, the more likely you are to avoid a mess in the future. When you do document your desires and wishes, think not just of the perfect world you wish existed. But rather, think of how things might go wrong (and with dysfunctional relationships they often do go wrong).