It's implausible to think that an alternate IJN that had decent radar by 1940 had not also worked out decent radios and fighter control.
Regarding priorities, everybody felt that Torpedoes were a bigger threat then dive bombers, against battleships. At the time most dive bombers carried 250kg bombs (apart from the Ju87) and battleships had that covered.
The IJN had ample information about how their own dive bombers had been effective against ships without armored decks (in fact inflated since they tended to over claim) and would have to be total morons not to regard dive bombers as a threat agains their carriers.
And the dive bombers would be coming at a higher altitude, and would probably be detected first.
Even if they only managed to divert four A6M-2, attacking without opposition and with are very different things.
So let's not fall into the: Let's change one thing and everything else stays the same trap...
Regarding priorities, everybody felt that Torpedoes were a bigger threat then dive bombers, against battleships. At the time most dive bombers carried 250kg bombs (apart from the Ju87) and battleships had that covered.
The IJN had ample information about how their own dive bombers had been effective against ships without armored decks (in fact inflated since they tended to over claim) and would have to be total morons not to regard dive bombers as a threat agains their carriers.
And the dive bombers would be coming at a higher altitude, and would probably be detected first.
Even if they only managed to divert four A6M-2, attacking without opposition and with are very different things.
So let's not fall into the: Let's change one thing and everything else stays the same trap...