Islands of Adventure is not random. Each 'island' is one specific theme or IP. Universal doubled down on that concept with the Potter Lands to great success. And yes, they still have random attractions scattered in their Studio Park, but, it would be wrong to say it's all just random. Potter and the 'islands' aren't randos.
Unless... you want to count that having all those different lands/islands in one park is random. In that case, I'd like to introduce you to Magic Kingdom.
MK had a bunch of random 'lands' (and don't tell me they're all based on 'magic' since Frontier Land and Liberty Square are historical, not magical). And each 'land' had a bunch of random IPs (original ones for the park and pre-existing movie IPs) loosely based on the theme of the land.
With WDW now embracing the one-IP-land model of Potter (and the Islands of Adventure), then WDW is become less of a random collection of IPs. Sure, a park having several unconnected lands may seem random, and again, for that, I give you the Magic Kingdom as the model.