The best thing Italy can do is can-open, period. The more mechs and men it has to do this, the better, and so a mixed 60/40 German/Italian front is fine. Russia will find it impossible to back-stack its reserve armies because they cannot screen the Italians out and then the German Armor will run through the holes the Italians make. Its devastating and its why the bid is pretty much required.
If Germany and Italy can both get StratBombers, even better because all of them can fly to China and start can-opening in waves, for Japan.
Italy often gets nerfed by Taranto, but in the case you get lucky or the player doesn’t do it, Going Italy + Bulgaria +SFrance + Paris + 19 IPC is awesome because you will have about 40-50 income on I4-5, and you’re like a baby Germany.
And, if they decided to KGF or KIF, you buy a bunch of fighters and men instead, projecting threat and preventing UK and US from coordinating their attacks.