The only thing wrong about this excellent arc are those two stooges who should have disappeared when they turn was over for the first time. I feel like they cheapen the arc even if, in theory, they are used to show Sanosuke is a straightforward and honourable guy, after a fashion. I suppose the author didn't want to come up with convoluted ways to make Sanosuke really want to fight Himura Kenshin no matter what. The stupid brothers were just a tool to make it happen as promptly as possible and for some sensible reason (they wanted to get rid of Kaoru and Kenshin is protecting her), and conveniently they knew who Kenshin really is. It's not like humour and heavy stories wouldn't fit together, but I'm not so sure about comedic idiots and heavy stories.