These two couples are very different.
It would seem that the relationship between Hero and Claudio is immature. They are attracted to each other physically but they really don't know each other, otherwise Claudio could not be convinced that Hero was unfaithful. It would appear that he trusts the word of Don John over his intended. Don John has not proved to be very trustworthy, yet the men believe him. Cleverly Don John plants the seed. Claudio excepts it. When he learns of the deception of Don John, he takes a journey where he grows and hopefully matures and becomes worthy of Hero's love at the end of the play.
In contrast, Beatrice and Benedick don't want to rush into any commitment. In fact they can't admit to themselves that they love each other. They are each guarding their hearts. They need their friends to help them realise that they, in fact, love each other. In fact Benedick's love for Beatrice causes him to side with her over his best friend because he trusts her. If she says Hero is innocent, she must be innocent.
In the end, it is a matter of trust. Claudio does not trust Hero; Benedick does trust Beatrice.