Shiv:
Yes, there are many sources like Finn MacCool, but Skalds are not how d&d Bards are generally portrayed these days. Mincing Minstrels in tights that sing, grant bonuses and are role-played like Junior Shakespeare in the Park thespians is what I see. Which is odd because you'd think that as a Jack-of-All-Trades the Bard would be interpreted broadly, but they aren't.
The only place I've seen them done interestingly is in 1e d&d. At least they were more like your Warrior-Poets or "Skalds". Gellor One-eye was definitely and adventurer and I can't imagine him in a puffy shirt with tights.
I have not myself seen anyone play a Bard in the way you describe; in 20+ years. Doesn't mean you are wrong and I am right.
Just means you cannot know everything from only your own perspective.
Most of the Bards I have seen are much more like, say, Tyrion Lannister, or the one dopey but awesome Zena sidekick, or like the above-mentioned Skalds (who did in fact wade into battle singing.)