The 25mm AA gun fired the twice as heavy shell than the 2cm Flak did, at the same velocity.
It was trade off, the French 25mm fired about 2/3 the number of shells per minute. and that is counting magazine changes.
Means it will ought to outrage the light Flak that Germans had in scores (= 1-barreled 2cm), and that seems to be so, 3000m vs. 2000m for the 2cm (terms and conditions apply). It will also have a better ceiling.
An awful lot depends on sights and mounting. I am rather suspicious of a lot of these light AA ranges. For a 3000m range for a gun with a 900m/s velocity that means a flight time of 3.3 seconds, not counting air resistance. Now how many of these light AA guns had sights that allowed for aiming even 3 seconds ahead of an aircraft? even a biplane flying 180kph moves 50 meters in one second. A 300kph plane moves 83meters per second.
The story of the Hotchkiss 25mm seems to be a little confusing in non-Japanese hands.
Wiki says that the Romanians ordered 300 guns but only got 72 before the war started. Most of the rest went to the French forces.
NavWeap's says the Romanian's didn't get any before the war but got most of the guns after France fell.
Anthony Williams says fewer than 250 guns (for everybody) were delivered by the summer of 1940.
The French navy didn't get any until after the war started, if not later.
The French Army got
around 200. Impounded Romanian guns or their own orders?
There were 2 or 3 different rates of fire depending on year of the gun. There were several different mounts, including twins.
Considering the rather dismal performance of the 25mm gun in Japanese service (unknown in 1940) it would seem that devoting any energy/money to any program involving the 25mm Hotchkiss AA gun would only benefit the Allies.
The Romanian time line is also skewed a little. Romania doesn't join the Axis until Nov 23 1940, at which point the Germans had moved around 500,000 troops into Romania in the last 6 weeks. Romanian relations with both Germany and Russia are somewhat twisted. Germany agreed for the Soviets to take back large areas of Romania when the Soviets 'occupied' eastern Poland. Then got Romania to help Germany in return for German help in regaining the lost territory. Germany isn't shipping much of anything to Romania until Dec of 1940?