Proportionate to the size of each company and the amount of toys they produce, I'll bet there's significantly more variety in Warhammer.

Just from a quick search, within a year Games Workshop offer about 3000 different model kits, each of which will contain ~1-4 unique moulded sprues. There seem to be at least 50 new kits each year, possibly 100, otherwise what's available rotates around the older kits.

Lego have produced about 15,000 different sets since 1950, and a huge number of the parts are shared between sets. (That's the whole point of the toy, no?)

Yeah I tried to look up the number of different Lego partszbut it gets hard to define what a Lego part is. And are we counting different colours, different designs printed on them, etc. Somewhere between 5k and 60k.

Also you have to take in account that Lego frequently stops certain parts and also that they more and more create complex parts and comparatively less "classic" bricks.

Which is an issue because it makes the sets way more difficult to reuse than 30 years ago. Go figure what to build with a random ninjago set except the official model. But that’s another ~~rant~~story.