Are there legitimate saints not documented (named) in western hagiology?
The short answer is: yes.
As in many situations, the Church assigns to them the date of November 1st as their feast day: Solemnity of All Saints.
Today the Church celebrates all the saints: canonized or beatified, and the multitude of those who are in heaven enjoying the beatific vision that are only known to God. During the early centuries the Saints venerated by the Church were all martyrs. Later on the Popes set November 1 as the day for commemorating all the Saints. We all have this "universal call to holiness." What must we to do in order to join the company of the saints in heaven? We "must follow in His footsteps and conform [our]selves to His image seeking the will of the Father in all things. [We] must devote [our]selves with all [our] being to the glory of God and the service of [our] neighbor. In this way, the holiness of the People of God will grow into an abundant harvest of good, as is admirably shown by the life of so many saints in Church history" (Lumen Gentium, 40).
The names of many holy martyrs are unknown to God alone. In cases where the names of the martyrs are not known, there is simply an entry for the group. For example: