Having read more books about World War II in the last year than I would have ever imagined, Patton, Montgomery, Rommel didn't offer much in the way of new information. A few anecdotes I either hadn't read or didn't remember, but in the broad strokes, not much new stuff.
It is a useful book for being able to compare and contrast the three, especially their egos. I'm not sure whose was the largest, but they were all convinced they were the best, that they should be given all the supplies and men they demanded, and that if their operations failed, it was because their bosses didn't accede to their wishes. The difference is that where Rommel was arguing with Hitler, who had total control and more than enough will and certainty he knew what was best to brush Rommel off whenever he felt like it, and Patton shot himself in the foot with indiscretions often enough he was lucky to even have a job, Monty was able to get his way some of the time, which only made him more prone to demanding it again later. I'm really stunned Ike was able to restrain himself from killing Monty, honestly.
Brighton does have an idea to explain Monty's caution - at least when facing Rommel in the desert. He argued it wasn't that Monty was incapable of aggressive, quick maneuvers, and later points to his early operations in Sicily and the ill-fated Market-Garden attempt. Rather Monty knew fighting a running, mobile battle on open ground would play to Rommel's strengths, and Monty was smart enough not to do that. I imagine Montgomery wouldn't have described it in a way that makes it sound as though his prowess was less than Rommel's - he'd describe it as a concern that his subordinates and troops couldn't have executed his brilliant plans quickly enough - but if Brighton's right, it's a smart move by Montgomery. He has the numerical advantage, he can win the war of attrition, especially if he makes Rommel come to him, fight on ground of Monty's choosing. So no reason to play his enemy's game. It's still commanding not to lose, rather than commanding to win, but it frames Monty's actions in a somewhat better light.
Actually, for the first third of the book, I thought Brighton was being extremely protective of Monty. Upon finishing the book, I decided it probably has more to do with the fact Monty's generalship has been questioned and criticized much more so than the other two. In some ways, I think the fact Monty lived far longer than the other two hurt him (and people like aggressive generals who take chances). It gave him more time to strut about taking credit for every success while deflecting all blame, and thus more time for people to get thoroughly sick of him and fire back. Of course, the idea of taking the high road never occurs to Monty, so he fires back at them, and it all just gets uglier. If Patton had lived even another five years, there's no telling how much damage he would have done to his memory with ill-advised words or deeds.
I am curious how things might have gone if Rommel hadn't been nearly killed by a strafing fighter airplane. As Brighton describes it, Rommel knew of the plan to remove Hitler (though there's no evidence he'd been told "remove" meant "assassinate"), but had drafted one last message to Hitler trying to make him understand the situation and think of what was in Germany's best interests, and was checking the loyalty of his subordinates in case he ordered them to lay down their arms if he tried to negotiate an armistice. Then he nearly died, and Hitler wasn't killed, and by the time Rommel was out of a hospital bed, the noose was already around his neck.
I'm curious whether it would have even worked. His subordinates said their loyalties lay with him, but would the rank and file have gone along? For that matter, would the Allies have accepted his offer? Rommel was apparently concerned that Berlin not fall into Soviet hands, and under that line of thinking, better to let the Americans and British get it first. Considering how many German soldiers and civilians fled the Russian side of Germany to hide under the Anglo-American alliance's umbrella, he was hardly alone in that belief. But FDR had been demanding unconditional surrender, and he wasn't alone in the desire to wreck Germany's ability or desire to make any more trouble militarily. Would he, Churchill, or Stalin have agreed to let the Germans surrender while still outside their own borders, considering how that went at the end of World War I?