Anyone playing any Gemmelian hero, to me, should be a proficient, seasoned, serious martial artist, rather than a box-offfice star with limited actual fighting prowess, like Brad Pitt or Eric Bana. Not that I have anything against either Brad or Eric, they're both great actors, I think. But if you wanna see realistic as well as beautiful, sophisticated moves with hard core fighting, then I dont think they fit the bill.
Someone of the calibre of Steven Seagal, Jean-Claude Van Damme, Dolph Lundgren or the likes of them, I'm thinking. Sorry I'm unable to quote other guys of the newer generation, cos my time was earlier. Maybe Jason Statham.
I'm rather surprised that nobody who produced any Van Damme movie never read any Gemmel book.