No, Ciaphas Cain is a Commissar, not a general. He's a political officer. His "thing" is that despite being a coward at heart who tries to avoid danger and stick to the back lines (just like Tanya), he always somehow manages to stumble directly into the conspiracy/alien force/flanking maneuver of the enemy instead, which is what makes people believe he's a selfless hero of the Imperium who wants nothing more than to "get stuck in" and thus more frontline assignments.
In his defense, he really does fight the enemy whenever he comes up against something and has personally faced more horrors (a Tyrannid Genestealar Patriarch, an Ork Warboss, several Chaos Space Marines and even a Daemon Prince of Slaanesh) in personal combat (though usually with the help of his aide). But he's nothing like Rommel here, who is a perfectly capable general who's just a bit eccentric.