If you notice in the link the mysteries as used by the RCs are included…something St Seraphim did not include. My point is why must everything we Eastern Catholics do be Latinized? Cant we just take our traditions as they are and accept them?
I agree with your concern - 100%.
In St Seraphim’s case, he insisted that his spiritual children say the Rosary/Rule daily and presented 15 mysteries that are different from those of the West. These began with the Nativity of the MHT, then the Presentation in the Temple, then the Annunciation, Visitation, Nativity of our Lord, the Meeting in the Temple, Flight to Egypt, Jesus teaching in the Temple, the Wedding at Cana, the Theotokos under the Cross, the Resurrection, Ascension, Pentecost, Dormition and the Holy Protection of the MHT.
I know this prayer is popular through Orthodox Russia and Ukraine. It is well written up in chapter six of the book: Staretz Zechariah: An early Soviet Saint.
Jordanville publishes a book on prayer rules in monasteries where mention is made of the consistent practice of Orthodox monastics saying 150 Our Father’s and 150 Hail Mary’s with a prostration after each prayer.
According to St Seraphim, this prayer was revealed to a monk in the Thebaid and from there it spread throughout the then still united Christian world. This makes eminent sense given the connections between the Thebaid and western Europe, St John Cassian and Lerins etc.
Alex