Yeah Shigechi wasn’t a likeable character, but I guess that was the point of him. Also he was fairly important to the story cause he basically kicked off all the Kira stuff along with Reimi. So sometimes unimportant characters are more important than you’d think.
Combat wise, Bad Company is superior. Keicho essentially has the firepower of a large platoon without the need of extra supplies, while Shigechi is pretty much just an obnoxious self-centered 8th-grader