Absolutely. It's Games Workshop's IP, it's theirs to make sure that they only entrust it to people who will make good use of it and theirs to make sure those projects are well run.
Reminds me about a story about JK Rowling during the early negotiations with Warner Bros about the Harry Potter films. They all sat down and Warners came up with a list of things that they said they were going to chang. JK Rowling stood up, wished them good luck and went to leave. They asked where she was going and she simply replied that they obviously had very clear ideas they wished to follow and that was fine, just not with her characters or books.
Now you can argue that she was being precious, awkward or whatever (I was going to write unrealistic but as she got her way she was being perfectly realistic it would appear) but whatever else she was doing, she was managing her IP in a way many others could learn from.
That might be true though she never changed her position on things - hence the almost entirely British cast, films that remain largely true to the books (within the limits of crushing 700 pages into two and a bit hours) and so on.
Obviously it helps with negotiations when you're holding all the cards as she was - owned what looks like it will be the most valuable franchise in film history, undoubtedly had competitors queuing round the block, didn't need the money...
