This is, I think, a new comparison strategy. Consider a pronoun that indicates that a thing is being compared. I'll be using italicized comp as this pronoun:
Between John, between Eric, the company relies on comp_masc,sg.
Between X between Y is considered to be similar to how Biblical Hebrew forms 'between', i.e. both nouns are preceded by the same preposition, possibly with an and, i.e. "between X and between Y".
If the compared things differ in gender, comp can by gender congruence relate to either of the nouns. For nouns of the same gender, the first noun is the more X:
between the brother and between the sister, their mother wants comp.fem.dat the painting as inheritance
the mother prefers that her daughter gets the painting as inheritance
between John and between Eric, comp.masc.nom is strong.
John is stronger than Eric
between Tor and between Sven, she likes comp.masc.acc
she likes Tor more than she likes Sven
between Schylla and between Charybdis, comp.fem.nom scares me
Schylla scares me more than Charybdis (does)
between John and between Tina, comp.fem.nom plays the guitar well
Tina plays the guitar better than John