Air defense is disabled during the first initial strike, just fyiThat completely understandable though I would probably use pearl harbor as a metric for what a good, unopposed attack would look like. This is completely deleting fleets under air cover which it really shouldn't.
Also I guess this test is done during optimal conditions where a large portion of the fleet (or the entire fleet for that matter) is in port, the carriers are in range unopposed. I think normally you would see the fleet being spread out, some at sea, and not everyone being at the same port.
I will admit that balancing it to being actual useful, fun to use (from a gameplay perspective) while also having it not being too powerful is certainly a difficult task. I can only speak for myself but my hunch is that seeing these optimal conditions in the actual game is gonna be rare, so you kinda have to balance it for sub-optimal conditions as well, since that is what I think people will experience most of the time, but it is something that we will have to see.
As always, community feedback is key to balancing these things, and I look forward to see people using this in gameplay scenarios