Cats definitely smarter.
Find me 6 or 8 cats ‘dumb’ enough to be coaxed into a harness in Sub 00 weather, wind howling, then be willing to haul one’s ‘fat arse’ through the snow.
Go on a trip and leave 3 cats with a bunch of food spread around the house, plenty of water, especially leave a dish of something they don’t like. You can be gone for a week and there will be food etc left.
Try that with a dog and ALL the food will be gone, water tipped over etc by the time you clear the driveway.
Try herding cats.....
How will your cats do with warning you/stopping an intruder breaking into your house? A little extra care and maintenance is worth that deterrent IMHO.