I agree - but!!!! While the will may stand all legal challenges there is nothing preventing those legal challenges from happening and tying up the estate for years.
Nothing against John T but I've also seen lawyers draw up a will with the specific intent of drumming up more business. I had one old girl that worked in my office (she was 76) whose aunt died (she was 95). The will was written about 10 years earlier distributing all the assets to her neices and nephews. The problem was she wanted that distribution process to take 20 years so as to give them time to be mature enough to handle the money they were coming into. Her neices and nephews were all in their late 60s to early 80s when she died.
The lawyer that wrote the will told them not to fear - he knew how to legally speed that process up. All they had to do was pay him and he'd make it happen.