I thought that you were talking about other bells.
Reality check -- most of the time, the Divine Liturgy is celebrated by one priest, with maybe one or two altar boys.  Few parishes have deacons. Altar boys can be scarce, as well.  It all depends on the parish.  
Re a procession around the nave -- I am not sure what you are talking about.  The Small Entrance is a procession with the gospel around the altar, out of the side door and back into the main door of the iconostasis.  The Great Entrance is from the table of the proskomydyya, out the side door and back through the main door of the iconostasis.  There is no procession around the nave of the church during the Liturgy.
I think that, at least in the Ukrainian Church, there might have been many more changes, had not the Ukrainian Church been in preservation mode, because of its banning by the Soviets.  But that's another conversation....