Starting with a list is good... Though at the end of the day you really just need counts of each character and star level for most characters.
If your guild has 10 lobots at 7*, you basically only have to worry about lobot if a mission requires more. Yes I had a shard mate whose guild got one that needed 11. Though from what I noticed 5-6 tended to be much more common so would probably make a better "alert" threshold.
Ok so you covered sheer numbers of pretty much useless characters... Don't need specific who has what here, cause if you have it, donate it.
What about battle critical characters? Chaze, Resistance, Wiggs etc This gets more complicated, how you sorta need who has what... but the what isn't the characters, but rather OTHER alternatives that can be used in their place. What members have a resistance team AND another lightside comp they can win with? THEY should be tasked to donate critical resistance members first.
Basically I think its cumbersome to track specific people and who has what for platoons. The effort should be tword teams that win the battles. More variations and alts you can find for those critical characters, the easier platoon management will get.