There is a lot in common with the cast of both Kenshin and Shinkenger. It's a samurai season which is another way to get interested in for, and both have a dark tone with a mix of satire.
Rurouni Kenshin: Kyoto Inferno (kyoto Taika hen) is the sequel to Rurouni Kenshin. It features the main characters and introduces Battousai's successor Shishio who tries to take over Japan. Can Kenshin beat Shishio while keeping Battousai at bay?
Although they are set in different eras, the movies are similar in their fight against an oppressive regime. They have a similar feel to it, in terms of action and the buildup to the climax. Both have very well shot action scenes and wonderful camera work.
Both have awesome swordsman and fight scenes. One is about getting revenge and killing while the other is trying to make amends for past and refuses to kill. Both are awesome movies and have the same feel and character looks.
Both are epic jidaigeki Samurai classic movies. Both movies are very similar. Rurouni kenshin tsuioku hen, past Arc, seems to be inspired by, homage to Fusa..................................
From what I can tell It's from the same era, and the story/characters are somewhat similar to each other. Dororo might have a slight different genre, tipping more over to fantasy and may seem a bit ridicolus at times, but still has a great cast.