I have to be fully transparent that I think both donors and ministers aren’t that well integrated. You start the game with a cabinet and donors (who presumedly supported you through your campaign to be initially elected) with random allegiances to various voter groups. To add to this, the pool in which you can replace ministers is too limited to form a cabinet which actually might help. I understand voter groups need to play a part in this, as not catering to your ministers can lead to an unstable govt. This is especially the case with donors, as not having enough donors can lead to you losing the game entirely. For example, why would a donor caring of Liberals support my campaign if my goal is to support Conservative policies?
My suggestion is another screen before you start the game, in which you pick your initial ministers (from a larger pool) and donors. At least then if they resign later on, it’ll be your fault.