When I readed "Legion", I could almost mistake the place for a space Afghanistan or Irak planet. (Desert place... Veiled guerillero warriors... Yeah...)
Sometimes, he seems to ripp-off idea, like the Megarachnid in Horus Rising, who seem A LOT like the bugs from Starship troopers, or Iron Snake who made me think of a WHK Rip-off of 300.
hell, he's an heck of a rip-off-man!
He writes in a simple pleasant way though, and his novels are entertaining enough to be remembered