Part of the problem is that I can exploit the homebrew rules, and more importantly, the monsters DO exploit them. So I might limit myself to as many 5e rules as I can, but the monsters and NPCs will not.
Also, I am a DM. However, even I can't remember who can cast what spell every time. So, in order to even play true to 5e, I have to constantly look things up myself and restrict myself if I want to play true to 5e... Which I do try to do. But sometimes I just say, ah forget it. Because I don't feel like looking it up, I just guess. That's frustrating and annoying.
So, you don't know who has the ability to cast Divine scrolls, and who can cast Arcane scrolls? Is this what you're saying here? With no context, this is what it appears to be from here.
5e spells are more specialized than just "Arcane" and "Divine." Some spells are available to wizards but not sorcerers; some spells are available to clerics but not paladins, etc.
There is ~some logic to who gets what spell, but remembering the class restrictions for every single spell sounds ~impossible.
