I don't want them to know the amount of spells as a full caster.
Something like 10-13 spells known at level 20. And most of the spells over 6th level would be improved or mass versions of lesser spells. Mass Heal, yes. Meteor Storm, no. Regeneration, yes. Earthquake, no.
Well, doesn't it require us to actually know what is in the bard's spell list before we can figure out whether being a "full caster" or "half-caster" actually matters? I mean... if Earthquake was on the bard's spell list, then "full" or "half" really doesn't make any difference at that point, because it's the spell itself (and not the amount) that is the issue there.
If people are associating "full caster" with "breadth of the Wizard's spell list!"... then sure, I'd understand their concerns. But that really can't be it, can it? No one actually believes that because the bard is "full caster" that the bard's spell list is now going to include all kinds of non-bard spells just to fill it out, do they? That seems like a jump in logic way too out there to believe.
That is the thing.
I don't mind if the bard has the slots for a full spellcaster. 4/3/3/3/2/1/1/1/1.
I don't want them to know the amount of spells as a full caster.
Something like 10-13 spells known at level 20. And most of the spells over 6th level would be improved or mass versions of lesser spells. Mass Heal, yes. Meteor Storm, no. Regeneration, yes. Earthquake, no.
Insufficient data.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.