i dont know about ichigo hollow form being the rawest... hes a bit overated, for the fact that he struggles most of the time with people the captains can take out easily... hes not even on byakuyas or kenpachis level...yeh you will say he equalled them in the begining but it was only bcoz it was how the story was meant to go... and not a true reflection of the captains powers... ichigo is kool, but he lacks
Kouga was too sure of the ultimate say of his weapon's ability. He should have thought better than believing he couldn't be overcome, and showed some restraint and smart caution in battle. He should always think, "But what if I CAN be defeated?" And a strong heart would mean having humility and the discipline to always be learning further self-improvement. He acted as though he thought of himself the one-person solution to the entire rebellion, overconfident he and his zanpakuto were invincible. This was evident by the way he presumed to get in and win every mini-battle with the rebels he came across and get to in time. All of that left it all too obvious a threatening conclusion to the insecure paranoia of his superiors.