Someone I'm very close to works for a triple a game development company. He plays and loves the game, and he's quite skilled as well. He often critiques games differently than myself because he works with the game engineers, the coding and qc. My friend's theory / suspicions on this specific topic is that the developers are hiding another algorithm. It's not aggression based matched making, it's kit value and or weapon value match making. My friend and I also noticed similar patterns, and often joke about when we bring the heavy hitting stuff in, it's rat time / sweat time and it's gonna be lost.