How short is short? You must calculate the wheelbase length and not the length of the whole car (including the front and rear overhangs). The wheelbase of b-segment cars are not really that much shorter than a larger C-segment. The short overhangs on the b-segment makes it look like a shorter vehicle.

A shorter wheelbase car will have less chances of losing the rear and that is correct but you have to be so so so so so so so much shorter. The only thing that comes to mind is actually the Smartfortwo. That car would have very little chances of losing the rear as it drives like a go-kart. Other B-segments cars will lose the rear just as easily when you lose control and that is where VSC/ESP/ETC/ABC/123 will come in handy (but not a guaranteed) to help stabilise the car.

Maybe I should not use 'drifting' as an example otherwise everybody thinks that a longer wheelbase car is oversteering into every corner.

It's more about the feel of the car, something quite difficult to explain on the Internet. A longer wheelbase car is more resistant to turning. You feel that you have to work harder to make it turn and once it turns, it is more difficult to change to the opposite direction (for example if you are entering a left corner that goes into a right corner).