Not really trying to convince so much as discuss, but in a nutshell: the level a paladin gains access to a spell is irrelevant to the level a bard gains access to a spell via secrets as far as power level is concerned. Getting access to a paladin specific spell is no more powerful than gaining access to any other spell on the paladin list that isn't paladin specific.
I disagree with the idea that a 2nd or 4th or 5th level spell is somehow more powerful because a bard
might have access to it earlier than a paladin when those spells are nothing more than another choice among many other 2nd or 4th or 5th level spells as far as the bard is concerned. It's not a power issue and it is the typical casters vs martials argument instead.
What matters is considering an ability iconic to the paladin placed within the spells and then seeing the bard take it earlier. This looks like it's getting corrected by limiting bard selection by class in the newer version.
Hopefully that helps clarify.