There may be a confusion: I wasn't talking about draganna per se, but more on the general topic of "every character that's related to book and/or teaching has very positive com AND good teacher". You might add "instead of just investing massively in teaching" 
Likewise, not being the best with insane totals doesn't mean that you're dismal. What 's the problem with a teacher that has, say, Com 1, teaching 5? That's a professional teacher, with a source quality of 1+5+3 = 9, +6 if teaching one-on-one, for a +15, a little more than an excellent tractatus.
Talking about mundane books, we have only one that exceed that (with a SQ of 23 
), 4 that equal it, and a lot more that are clearly inferior.
To take back your example, you rolled back your warrior because you wanted him to be a great warrior and he was dismal. And that's fine, he's a hero and supposed to be an exceptional character. But what if just every NPC city guard of whatever had Str and Con of 16+?
Yeah, like your knowledge of Lores Or the fact that, in teaching them in AL or philosophiae, you're still better than reading a book, despite you not being, at least potentially, one of the best teachers in the whole world.
For exemple, look at this guy:
Com +2, teaching 2, SQ one-on-one of 4+3+6 = 13. Still quite good compared to most books (and I'm refering to the Andorra Library here). Despite not being a professional teacher, he's still useful as one, because he can train magi a little better than most books, to a better level, especially in Artes Liberales, where he'll push you farther than just about every book. Hell, even in Philosophiae, he might be worthwhile!