It seems that for some high-level spells, the number of scrolls you're assured to be able to attain (through fixed drops, rewards, containers, and stores) can be scarce enough that you can't have all your mages scribe every spell in the game unless you're lucky enough to get additional rare scrolls as random drops. Correct me if I'm wrong.
Furthermore, some scrolls can't drop randomly at all unless you install the corresponding component of SCS. I'm assuming that this mostly affects high-level scrolls, effectively making sure that you can't ever attain more than X amount of certain powerful scrolls throughout the whole saga.
In my case I'll have three mages starting from mid-SoA: my PC who's a fighter/mage, Imoen, and Aerie. I intend to keep them throughout the saga (until the end of ToB).Given that, is there anything I should be highly cautious of with regard to who gets to scribe which scrolls?
For example, right now the way I use my F/M PC is that I only have her cast battle buffs for difficult fights to become a near-invulnerable tank; otherwise she just runs around with armor and functions as a regular fighter. Now I'm not really sure if this is how I should be using an F/M at later stages of the game but if so, it would mean that she doesn't need any direct-damage spells and should instead just make sure to scribe all the battle buff spells like Mantle, Protection from Energy, Absolute Immunity etc.
Any thoughts/suggestions/warnings? Am I over-analyzing?