Hey Wayneos - I would be a little cautious about that info. I heard some stuff from some of the people working the Grenadier booth when I saw the vehicle at the Overland Expo in Colorado that was flat out wrong. Some of it was pretty basic stuff.
Rock sliders are beefy hunks of steel. They are designed to support the entire weight of the vehicle if you happen to perch the vehicle on top of your slider. As an added bonus, because they are designed to support the vehicle, they can be used as jacking points to change a tire or for a sketchy extraction.
I have never encountered a side step that can do any of the things that the rock slider is designed to do. They are typically just a step to get into the vehicle. I'd be very surprised if the side steps on the Grenadier can support the weight of the vehicle, and I think if you used them for this purpose you would damage the rocker panel and maybe the door as well. They may bolt to the frame in the same location that the rock sliders bolt to the frame, but that does not mean they have the same strength.
One way to check would be to compare the price of the two: if the side steps are significantly cheaper, there is no way they double as a rock slider.
A second way to check would be to compare the weight of the two. I think someone posted that the rock sliders were between 50-55 kg for the pair (110-120 pounds). That is spot on for a set of rock sliders (the sliders on my truck are 115 pounds; the beefiest set I saw for my vehicle were 150 pounds). See if you can find the weight of the side steps - if they are significantly lighter there is no way that they are "structurally similar" to the rock sliders. I'm going to guess that the side steps weigh around 20 kg (plus or minus 5 kg). They will be great as a step, and depending how you use the vehicle, they may be the best solution for your needs. But if you drop down onto a rock and land on the side step, it will bend, and could be forced into the rocker panel, or even into a door.
If you find the weight for the side step could you post it here - thanks!