The shape developes as they grow.All the Andinoacara have the same basic fry/juvi shape...one reason they all got lumped in the same genus (for now).
To me,the Blue Acara species develop a more Aequidens ( "Acara" ) shape as they age,which is what you are noticing.
They are going to end up eventually splitting Andinoacara apart anyway,with the GT-ish species ending up in their own new genus.
Far as my personal preference among the "Blue Acara" I like...A. coeruleopunctatus
.No confusing it.