so, for example, there's the part where he talks about islam's indebtedness to iranian culture, which is an often overlooked point that i've drawn a lot of attention to in debunking the so-called "islamic golden age", which was a kurdish-led babylonian renaissance that the islamic authorities eventually suppressed. you have to give the arabs credit for ending the damned war, which was a pre-requisite for the renaissance to occur within. but, not only did they have nothing to do with it, but they shut it down by force...
likewise, the destruction of carthage is important to take note of, but i think he frames it poorly. yes - it was unoriginal, and that was the point, as the arabs of the time (which were a multiethnic force consisting pre-dominantly of former roman citizens or former roman tributaries) saw themselves as carrying out a conquest of the roman empire. so, they copied the romans because they considered themselves a purifying force in roman civilization. this continued all the way to 1452, when the turkish sultan declared himself emperor - to howls of laughter from europe and asia, combined. yet, the "sultanate of rum" carried forwards for centuries.
when they carried forward to spain, and tried to invade france, and held out in sicily, and conquered greece....it was all about being the new rome, as the old rome had collapsed into decadence and corruption. there's some ironic reading of gibbons for you, but it's true - it's how they saw themselves.
so, carthage had to be destroyed to bring roman civilization back to god. that was what the muslim armies saw themselves as, as the christians interpreted them as foreigners intent on enforcing an alien culture - which is just what the romans thought of carthage, too.
in the end, the arabs did not just rebuild carthage but rebuilt the carthaginian empire. like the phoenicians, they were traders, in the end, and we owe our concept of modern european capitalism quite dominantly to medieval arabism.