I don't know why, but yeah, I kind of pictured him unconsciously as Scrimgeour as well. Jo described him as looking like an old lion, and it was Bill Nighy's face I pictured right away...don't ask how. I guess I'd say he has a "lion-esque" facial structure.

But Minister of Magic aside, Rufus Scrimgeour is not a 'good guy'. He's not evil, but after his introduction in HBP, all he's done was attempt to persuade Harry to be the Ministry's poster boy and withold Gryffindor's sword from the trio despite it stating in Dumbledore's will clearly that it was meant for them.

That was the last thing before he died too, so despite him not being a nasty piece of work like Umbridge, I'm still not particularly a fan of Scrimgeour, no.