Those are great points. I mentioned earlier that Kido Butai's fast carrier force sailed ahead of the main body in order to perform a "surprise" attack. This decision by itself led to the loss of three carriers. So in order for my scenario to be true, it requires the following assumptions:
- IJN doctrine changes to favor defense instead of offense. IJN strike forces used large numbers of dive and torpedo bombers escorted by proportionately smaller numbers of fighters. 68 to 90 additional CAP fighters would have made breakthrough difficult and improved Zero escorts.
- IJN leadership changes its doctrine in at least 1940. Taiyo and Unyo needed arrestor gear and squadron training to operate in the main body of Kido Butai. Both ships ferried aircraft and trained pilots as they were designed to accommodate biplanes.
Given the history of defensive vs. offensive warfare, I don't think IJN leadership, realistically, would change their doctrine. But if you can accept the conceit that doctrine could change in 1940, then the infrastructure could change too.
If doctrine changed, then the IJN fast carriers that got smashed at Midway would have had the protection of the main body plus its radar: Ise and perhaps Hyuga in a Japanese source were equipped with prototype Type 2 radar. However, an English-language source claims these radars were removed in May of 42. In any event, the Type 2 is said to have a range of 55 kilometers for aircraft and 20 kilometers for ships. Wikipedia claims a range of around 130 KM.
A very good source claims only Hyuga had radar at Midway.
Regarding the aircraft equipped on each carrier, the listed numbers include both Claude and Type 96 bombers. The Type 96 is significantly larger than the Claude. So it's likely that the Hosho would be able to carry more fighter aircraft, if it dispensed with bomb ordnance and bombers. I believe my estimate of 68 to 90 Claudes is conservative, although it does include the spares.
That's new to me. Hosho probably couldn't be released from ASW and scouting without placing burden on some other aircraft carrier or float plane attached to the main body.
Without Hosho's scout planes, I don't think the Main Body loses much, though, the Type 96 made the Devastator look like a modern aircraft. And its range was poor compared to newer aircraft. Additionally, the Type 96 was large and heavy. (And they also already had radar aboard at least one ship.)
Dispensing with the bombers and bombs would free up a fair amount of space for Claudes. Small size is one of the main advantages of the ultra light fighter concept: more can be squeezed into a space-constrained hangar on an obsolete carrier which can't launch much else. In other words, a carrier force could use the previous generation aircraft in a way that maximized their utility.
IMO, there are a lot of problems with the concept but if there is one application, it's to utilize scarce resources to their fullest, by maximizing protection of a critical resource.