The pastors described in Isaiah 56 seek their own good at the expense of the sheep, they do not possess the knowledge needed to guide the sheep, and they do not do the hard work of warning and protecting the sheep.
Instead of v. 11 speaking of female deacons, the alternative explanation is that Paul has lesser requirements for women because they do not actually hold office.
Is the pastor a third office in addition to elder and deacon? Or is the pastor an elder who has the special task of teaching and preaching in addition to ruling?