I was involved in some of the ‘paperwork’ that Cardinal Maida asked for before the last round of consolidations and closings.
One of the biggest factors was the “Sacramentality” of the parish, how many Baptisms, First Communions, Confirmations and Weddings was the parish involved with. That is (and should be) the primary concern of priests, and thus the primary concern of the bishop. To place the priests where they can do what no one else can.
The financial viability of the parish was actually quite secondary. If a parish had a vibrant Sacrament life, but could not make budget, the Cardinal was VERY willing to work with them. Holy Reedemer and Ste. Annes are a great examples.
In the case of a number of inner city parishes, most are in severe decline in the Sacraments. Very few Baptisms, First Communions etc…and therefore often need to share a priest.