The striker system on the Glock and XD is totally different, the Glock’s striker when armed is under a partial load, this load is what pushes the trigger forward to the ready position and when you pull the trigger the bar compresses the striker back and then cams down releasing the striker’s catch.
The XD’s striker when armed stays at full load, pulling the trigger just pivots the sear down and releases the striker’s catch.
Both pistols have firing pin safeties and should the striker release with out the trigger being pulled, a discharge will most likely be prevented, however the XD is not as safe as the Glock in this aspect and not just because it’s striker is under full load and the Glock’s isn’t.
The XD’s firing pin safety works by blocking the striker’s catch, this is a stress area and is always under full tension when cocked, if the catch breaks off due to fatigue, manufacturing defect, etc there’s nothing for the firing pin safety to block and the pistol will discharge.
The Glock’s firing pin safety works by blocking the firing pin itself, should the striker’s catch break off full forward movement of the firing pin will still be stopped.
(Slides from my G17L and XD40 Stainless)