Well this topic might explain a few things.
https://forums.galaxy-of-heroes.starwars.ea.com/discussion/259716/request-for-official-comment-on-squeeze-gac-league-and-division-targets#latest
Kyber is shrinking.
I started in A3 and moved up to K4/K3. I then went backwards with the (then) new 3 defensive ship introduction. I'm now swirling between A3-K4 (mostly being in A2). However, I'm significantly better than when I was in K4 just before the introduction of the extra ship.
So........things are definitely getting harder. Kyber has shrunk, the part timers have dropped down the leagues and those little sluggers coming up are blinking frightening!!
Although the instances you describe are mismatches on paper. The actual battles you're describing are competitive. That's how it should be.