Do NOT agree with Nolan on many of Batman's rogues gallery being 'Watered down Joker's', just like I don't agree that the Penguin would be too 'tricky' to do in the movies either. Take the time and read the Penguin's one shot in the 'Joker's Asylum' series, or the recent limited series, "Penguin: Pride and Prejudice" and it's apparent that the Penguin is extremely ruthless, but far from anything that can remotely be suggested as Joker-lite, and a interesting villain in his own right. The Riddler and others I could mention fit into this as well. But if that's Nolan's perspective, ok. Fine. Whatever.
Guess you really can't add a whole lot of depth to a villain when before each take, Schumacher was apparently telling the crew:"Now remember folks, it's a CARTOON!!!"
The Penguin is nothing like the Joker nor is he as far fetched as Nolan claims. The penguins aspirations run from politics (while Danny Devitos character did stray from the true essence, the framing of batman and running for mayor are both right up the characters alley) to arms dealing;