The numbers don't tell the whole tale. There were well over 2000 Cr.32s or 42s in Italian inventory when the war broke out but none of these were front-line fighters, they were phased out into training units and were so obsolete they couldn't even perform as night bombers. Yet the next most common plane produced in the war, the C.202, was the frontline fighter, and took over and surpassed its predecessors (c.200/g.50), and was the most common plane after 1941 to engage the allies. The C.202 only had 1500 built.
What?
The Regia Aeronautica's OOB on June 10th, 1940 (the day Italy entered the war with France);
1^Squadra Aerea3^ Stormo-Cr.42
53^ Stormo-Cr.42
54^Stormo-C.200
9^Gruppo-Cr.42
2^ Squadra Aerea1^ Stormo-Cr.42/32
6^ Gruppo Autonomo-C.200
3^ Squadra Aerea51^ Stormo-G.50
52^ Stormo-G.50/Cr.32
4^ Squadra Aerea2^ Gruppo Autonomo-Cr32
Aeronautica della Sardegna3^ Gruppo Autonomo-Cr.32
Aeronautica dell'Albania160^ Gruppo Autonomo-Cr.32
Aeronautica dell'Egeo163^ Squadriglia Autonomo-Cr.32
Aeronautica della Libia2^ Stormo-Cr.32/42
10^ Gruppo-Cr.32
Aeronautica dell'AOI410^ Squadriglia Autonomo-Cr.32
411^ Squadriglia Autonomo-Cr.32
412^ Squadriglia Autonomo-Cr.42
413^ Squadriglia Autonomo-Cr.42
Total fighters in frontline service available on June 10th, 1940- 77 C.200's, 88 G.50's,
177 C.32's and 200 Cr.42's. Much of the fighting in France by the Regia Aeronautica was fought by Cr.42's of 1 Squadra Aerea. Outnumbering the French, the Cr.42's still did poorly against D.520's and Ms.406's.
When Italy finally started participating on in the Battle of Britain in October 1940, they're contribution to the front was
50 Cr.42's, 48 G.50's, 75 Br.20's and 5 Z1007's.
Again in Greece and Albania, most of the fighting was done by G.50's and Cr.42's.
Again in Africa, near the beginning of the war in the theater, the Regia Aeronautica's presence in the region consisted mainly of Cr.42's, G.50's and C.200's, with C.202's being slowly phased in.