Re: Admiral Scissor's death, I actually think there's a worldbuilding aspect, that makes it entirely possible that he wasn't as strong as current Admirals or SenGarp duo.
To put it simply, it would look terrible for the WG to have one of their strongest fighters be slayed by a stripling like Rocks.
So I could definitely see SenGarp and other marines be put through more grueling training and higher standards to make them more capable against high level threats like Rocks.
It'd be like the irl phenomenon of predator-prey arms races leading to situations like T. Rex vs Trike.
Plus I'm sure the stronger Marines like SenGarp could have seen Scissor's death as incentive to train even harder.
Not entirely a powerscaling thing, just something I envisioned as a possible consequence of this incident.