Er, no. The G.52 and the G.50V are two different aircraft. The G.52 was one of the winners of the Caccia I (Intercettore, Interceptor) competiton of 1938-39 that not directly specified a radial engine, but almost all the submission had one. The other were the Macchi C.201 (powered by an A.76), the Re-2000 and the Nardi FN-530. With the exception of the Re-2000, which was company-funded, no-one of the three winners were ever to fly. Only one MC-201 was actually built, but never received the engine. In 1939 Regia Aeronautica decided to switch to in-line engines for the fighters, first with the DB-601 and later with the FIAT A.38 and various Isotta Fraschini projects. The A.38 was a bloody fiasco, and the I.F.s weren't very succesfull either. All the order were so cancelled in March 1940. Simultaneously, R.A. ordered Macchi to convert the the second MC-201 prototype in construction to receive the DB-601, and this is the birth of the MC-202, and Reggiane to do the same with the Re-2000, and this is the birth of the Re-2001. The decision to at all effects declare void the results of the Caccia I competiton opened the floodgates. Every major fighter manufacturer in Italy tendered one or more projects. FIAT proposed the G-50V, a normal G-50 with a a DB, the CR-42DB and a previously unknown CR-35 with a DB (found it in FIAT archives when researching the CR-44, my friend...), and did a study of a G-52 with a DB (but AFAIK never tendered it). FIAT was already concentrated on the G-55 that had to be powered by his A.38, and even did a study for an alternate project, the CS-38 by Manlio Stiavelli of CMASA.
As a finale, a G-5something was actually built with the A.76 (an engine that was another failure, BTW), it was the G-50ter, but this is a much later story, 1941.