What men need.
Priests do not so much need spiritual mothers, as they all have the perfect Mother in Our Lady Mary, Mother of Christ, Queen of the Clergy. While a devotion consisting of spiritual motherhood for priests may be efficacious, what priests most need are strong, manly fathers and brothers; most especially they need solid, strong, supportive, manly Bishops. (And the prayers of the faithful of course.)
Normally, one mother is more than enough for a guy - just ask St. Augustine. ;)