That's assuming there's much of a defense left, especially as the Marines aren't going to destroy the first wave without heavy losses, given the cruisers supporting the landing.
Three hours of shelling, especially by 8" gun cruisers, would have about the same effect as the pre-invasion bombardment had at Tarawa, none at all. Unlike the USN at Tarawa, the cruisers had no way to communicate with the landing force, and not even exercised with the landing force in advance. To reach their designated bombardment positions the IJN force was going to have to make a sustained 35 knot sprint to cover the distance between the ships they were escorting and Midway. That hardly allows for much in the way of spotting. All fire would have been made in the dark, when the cruiser's float planes would have been of minimal use as spotters (while being perfectly lovely targets for the radar aimed 3" DP of the defenders) since the PLAN called for the invasion to begin at first light.
I wouldn't bet against the Marines collecting one of the cruisers with their 7" naval rifles (these were the 178mm guns that has served as the secondary battery on the
Connecticut & Mississippi classes of pre-dred BB). These guns could punch through 5.5 inches of side armor at 6,000 yards, 3.9 at 9,000 yards. The Japanese
Mogami class CA (the class that made up CruDiv 7, the ships assigned to complete the bombardment) had an armored belt of 3.9 inches max thickness, with her deck and turret armor being 1-1.5" thick.
Once that was done the Japanese planned to conduct their amphibious landing using motor launches and towed barges (as they used in the DEI and in the Philippines), dropping their troops 200-400 yards away from the Islets themselves due to the reef, requiring the attackers to climb over the reef and wade in chest deep water through the lagoon. Those troops would have had four 7", five 5", and four 3" anti ship guns, 3" DP guns (24 of them), eight 37mm DP, 18 20mm (AAA but the mounts allowed them to be used in the anti barge role), 48 .50 cal & 36 .30 cal machine guns, a platoon (six IIRC) of M-3 light tanks (37mm main gun, FOUR .30 cal hull mounted plus 1 .30 or .50 on a pintel). This is before the 3,500 men of the defense force start to use their personal weapons (including BAR and Tommy Guns) and before the Japanese troops get to the shallows, where the Marines had laid electrically detonated mines, tanglefoot barbed wire, and around 1,500 IDE (idle hands are the devil's workshop).
As a comparison the Japanese had eight 75mm (3") DP guns, six 80mm anti boat guns (two triple batteries), two twin mounted 127mm (5") anti-ship guns, four 140mm (5.5") anti-ship guns, and four 8" naval rifles and 19 light Type 95 tanks as well as some 70 & 75mm howitzers and some 37mm anti-tank guns in addition to machine guns in both 13mm (.50 cal) and 7.7mm (.30 cal).
The Japanese defense force consisted of around 3,000 men plus some Japanese & Korean laborers. The USN shelled Benito for an hour and a half using 12 battleships (all of which were carrying mostly bombardment shells), 12 cruisers, and a couple dozen destroyers while using the airwings from a dozen CV and CVL as well as five CVE for air support prior to and during the assault. The American assault force was 35,000 men, or roughly 10-1 advantage in troops, many of whom made it to the beach in amtracs in the first wave (before the Japanese defenders blew most of the amtracs into junk). The Americans managed to land several tanks on Benito (the Japanese assault force for Midway had NO heavy weapons) which provided considerable cover fire, and the 8th Marines managed to get some 75mm pack howitzers onto the Beach as well, something else the Japanese lacked.
Despite that massive display of firepower leading up to and after the landing, which is WAY beyond Yamamoto's wildest dreams, and facing a 10-1 disadvantage in troop strength (while facing troops that could call for naval gun and/or air support at will) the Japanese still managed to inflict ~1,700 KIA and ~2,300 WIA on the American attackers. These number would have been considerably higher if the Japanese commander had not been killed on the second day of the assault.
In any case, the U.S. suffered roughly 4,000 casualties taking Tarawa, despite all the advantages I have noted. The ENTIRE Japanese assault force for Midway was 2,500 men.
8-5 the Japanese don't get more than 250 living, armed troops to the beach.