Cap. II Sol. Arg. 6: conjungit — elect to become rich in faith, not because foreseen rich
That is why he binds the two phrases: rich in faith, and heirs of the kingdom. He did not say the elect are heirs because they were foreseen as going to be rich in faith. He said they were elect so they would become rich in faith — and heirs of the kingdom.
Latin
Atque hinc est quod conjungit haec duo, divites in fide, & heredes regni. Non dixit electos heredes regni, quia praevisi erant futuri divites in fide, sed electi erant ut fierent divites in fide, atque heredes regni.