Why swapping Axis fleets cripples Italy and Japan

What happens if Germany, Italy, and Japan exchange their navies at the start of the Second World War?

Germany gains the strongest fleet, but Italy and Japan are strategically crippled because their replacement fleets do not fit their theaters, missions, or industrial support.

Italy would receive a much smaller fleet than its own and lack the industrial capacity to expand it rapidly. Japan would lose its carrier force and inherit Italian ships designed around Mediterranean distances, speed, and operating conditions. Their limited range would make Pacific operations much harder. Germany would acquire the strongest fleet of the three, but some Japanese ships are judged too lightly built for prolonged North Sea and North Atlantic punishment. With Italy and Japan substantially weakened, Britain could concentrate more of the Royal Navy in home waters. That would put its strongest effort close to its principal bases and supporting industry.