Remember Father Fenton never taught that Robert Bellarmine erred on the issue. Rather he clarified how others misinterpreted his teaching:
When Fr. Journet objects against St. Robert's omission of the factors which, for him, constituted the "soul" of the Church from his definition in terms of membership, he betrays a serious misconception of St. Robert's procedure and habitual terminology. Fr. Journet, as a matter of fact, builds his central concept of the Church around the notions of "soul" and "body". He distinguishes sedulously between the uncreated Soul of the Church and its created soul. For him, as we shall see, the "souls" and the "body" go together to form the Church itself.
Fenton